\(So\text{ }Sánh\text{ }-\frac{1}{5}\text{ }\text{ }\text{ }\text{ }và\text{ }\frac{1}{1000}\)
câu này dễ nhưng đố làm dc đó
Những câu hỏi liên quan
Bài 4: Tính hợp lý
A=\(\frac{4}{\text{1⋅2}}+\frac{4}{\text{3⋅5}}+......+\frac{4}{\text{20⋅11⋅2013}}\)
Bài 5: So sánh với 1:
A=\(\frac{1}{\text{1⋅2}}+\frac{1}{\text{2⋅3}}+\frac{1}{\text{3⋅4}}+......+\frac{1}{\text{49⋅50}}\)
Bài 5 :
\(A=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{49.50}\)
\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{49}-\frac{1}{59}\)
\(A=1-\frac{1}{50}\)
từ trên ta có : \(1-\frac{1}{50}< 1\)
\(\Rightarrow A< 1\)
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( Câu siêu khó dành cho học sinh đội tuyển Toán )( Giúp với )Bài 10 :b) frac{left(text{13}frac{text{1}}{text{4}}-text{2}frac{text{5}}{text{27}}-text{10}frac{text{5}}{text{6}}right).text{230}frac{text{1}}{text{25}}+text{46}frac{text{3}}{text{4}}}{left(text{1}frac{text{3}}{text{7}}+frac{text{10}}{text{3}}right):left(text{12}frac{text{1}}{text{3}}-text{14}frac{text{2}}{text{7}}right)}
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( Câu siêu khó dành cho học sinh đội tuyển Toán )
( Giúp với )
Bài 10 :
b) \(\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{2}\frac{\text{5}}{\text{27}}-\text{10}\frac{\text{5}}{\text{6}}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\left(\text{1}\frac{\text{3}}{\text{7}}+\frac{\text{10}}{\text{3}}\right):\left(\text{12}\frac{\text{1}}{\text{3}}-\text{14}\frac{\text{2}}{\text{7}}\right)}\)
\(\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{2}\frac{\text{5}}{\text{27}}-\text{10}\frac{\text{5}}{\text{6}}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\left(\text{1}\frac{\text{3}}{\text{7}}+\frac{\text{10}}{\text{3}}\right):\left(\text{12}\frac{\text{1}}{\text{3}}-\text{14}\frac{\text{2}}{\text{7}}\right)}=\frac{\left[\text{13}\frac{\text{1}}{\text{4}}-\left(\text{2}\frac{\text{5}}{\text{27}}+\text{10}\frac{\text{5}}{\text{6}}\right)\right].\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{100}}{\text{21}}:\frac{\text{-41}}{\text{21}}}\)
\(=\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{13}\frac{\text{1}}{54}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\frac{\text{25}}{\text{108}}.\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}\)
\(=\frac{\text{53}\frac{\text{1}}{\text{4}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\text{100}}{\frac{-\text{100}}{\text{41}}}=\text{-41}\)
Giải :
\(\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{2}\frac{\text{5}}{\text{27}}-\text{10}\frac{\text{5}}{\text{6}}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\left(\text{1}\frac{\text{3}}{\text{7}}+\frac{\text{10}}{\text{3}}\right):\left(\text{12}\frac{\text{1}}{\text{3}}-\text{14}\frac{\text{2}}{\text{7}}\right)}=\frac{\left[\text{13}\frac{\text{1}}{\text{4}}-\left(\text{2}\frac{\text{5}}{\text{27}}+\text{10}\frac{\text{5}}{\text{6}}\right)\right].\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{100}}{\text{21}}:\frac{\text{-41}}{\text{21}}}\)
\(=\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{13}\frac{\text{1}}{54}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\frac{\text{25}}{\text{108}}.\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}\)
\(=\frac{\text{53}\frac{\text{1}}{\text{4}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\text{100}}{\frac{-\text{100}}{\text{41}}}=\text{-41}\)
~~Học tốt~~
\(\text{Giải :}\)
\(\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{2}\frac{\text{5}}{\text{27}}-\text{10}\frac{\text{5}}{\text{6}}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\left(\text{1}\frac{\text{3}}{\text{7}}+\frac{\text{10}}{\text{3}}\right):\left(\text{12}\frac{\text{1}}{\text{3}}-\text{14}\frac{\text{2}}{\text{7}}\right)}=\frac{\left[\text{13}\frac{\text{1}}{\text{4}}-\left(\text{2}\frac{\text{5}}{\text{27}}+\text{10}\frac{\text{5}}{\text{6}}\right)\right].\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{100}}{\text{21}}:\frac{\text{-41}}{\text{21}}}\)
\(=\frac{\left(\text{13}\frac{\text{1}}{\text{4}}-\text{13}\frac{\text{1}}{54}\right).\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\frac{\text{25}}{\text{108}}.\text{230}\frac{\text{1}}{\text{25}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}\)
\(=\frac{\text{53}\frac{\text{1}}{\text{4}}+\text{46}\frac{\text{3}}{\text{4}}}{\frac{\text{-100}}{\text{41}}}=\frac{\text{100}}{\frac{-\text{100}}{\text{41}}}=\text{-41}\)
\(\text{~~Học tốt~~}\)
Xem thêm câu trả lời
bai 1 \(\frac{-3}{\text{2}}+\frac{5}{7}+\frac{-31}{14}< hoac=\text{x}< \frac{1}{\text{2}}+\frac{1}{3}+\frac{1}{6}\)\(\frac{1}{6}\)
bai 2 \(\frac{\text{x}+4}{\text{x}-\text{2}}+\frac{\text{2}\text{x}-5}{\text{x}-\text{2}}\)la so nguyen
Bài 1 mk ko hiểu đề cho lắm
Bài 2 :
Đặt \(A=\frac{x+4}{x-2}+\frac{2x-5}{x-2}\)
Ta có :
\(\frac{x+4}{x-2}+\frac{2x-5}{x-2}=\frac{x+4+2x-5}{x-2}=\frac{3x-1}{x-2}=\frac{3x-6+5}{x-2}=\frac{3\left(x-2\right)}{x-2}+\frac{5}{x-2}=3+\frac{5}{x-2}\)
Để \(A\) là số nguyên thì \(\frac{5}{x-2}\) phải là số nguyên \(\Rightarrow\) \(5⋮\left(x-2\right)\) \(\Rightarrow\) \(\left(x-2\right)\inƯ\left(5\right)\)
Mà \(Ư\left(5\right)=\left\{1;-1;5;-5\right\}\)
Do đó :
| \(x-2\) | \(1\) | \(-1\) | \(5\) | \(-5\) |
| \(x\) | \(3\) | \(1\) | \(7\) | \(-3\) |
Vậy \(x\in\left\{-3;1;3;7\right\}\) thì A là số nguyên
Chúc bạn học tốt ~
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bai 1: Viết tập hợp A các số nguyên x biết:
cau hoi cua phung minh quan
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Xem thêm câu trả lời
So sánh :
\(\text{}\text{}\text{}\text{}\frac{1}{32}+\frac{1}{33}+\frac{1}{34}+...+\frac{1}{90}\)Và \(\frac{2}{3}\)
Mk cần gấp giúp mk vs ạ! Thanks các cậu
\(A=\frac{1}{32}+\frac{1}{33}+\frac{1}{34}+...+\frac{1}{90}\)
Tổng trên có số số hạng là: \(\left(90-32\right)\div1+1=59\)
\(\frac{1}{32}+\frac{1}{33}+\frac{1}{34}+...+\frac{1}{90}\)
\(>\frac{1}{45}+\frac{1}{90}+\frac{1}{90}+...+\frac{1}{90}\)
\(=\left(\frac{1}{90}+\frac{1}{90}\right)+\frac{1}{90}+\frac{1}{90}+...+\frac{1}{90}\)
\(=\frac{60}{90}=\frac{2}{3}\)
Đoàn Đức Hà: Tại sao dòng số 4 phân số đầu tiên lại là \(\frac{1}{45}\)ạ?
Thực hiện phép tínha) frac{text{x + 9}}{x^2 - 9}-frac{text{3}}{text{x^2 + 3x}}b) frac{text{3x + 5
}}{text{x^2 - 5x
}}+frac{text{ 25 - x
}}{text{25 - 5x
}}c) frac{text{3
}}{text{2x
}}+frac{text{3x - 3
}}{text{2x - 1
}}+frac{ 2x^2 + 1
}{text{4x^2 - 2x
}}d) frac{text{1}}{text{3x - 2 }}-frac{1}{text{3x + 2 }}- frac{text{3x - 6}}{text{4 - 9x^2}}e) frac{text{18 }}{text{(x - 3)(x^2 - 9) }}-frac{text{3 }}{text{x^2 - 6x + 9 }}-frac{text{x}}{text{x^2 - 9}}g) frac{text{x + 2 }}{text{x + 3 }}-frac{text{...
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Thực hiện phép tính
a) \(\frac{\text{x + 9}}{x^2 - 9}-\frac{\text{3}}{\text{x^2 + 3x}}\)
b) \(\frac{\text{3x + 5 }}{\text{x^2 - 5x }}+\frac{\text{ 25 - x }}{\text{25 - 5x }}\)
c) \(\frac{\text{3 }}{\text{2x }}+\frac{\text{3x - 3 }}{\text{2x - 1 }}+\frac{ 2x^2 + 1 }{\text{4x^2 - 2x }}\)
d) \(\frac{\text{1}}{\text{3x - 2 }}-\frac{1}{\text{3x + 2 }}- \frac{\text{3x - 6}}{\text{4 - 9x^2}}\)
e) \(\frac{\text{18 }}{\text{(x - 3)(x^2 - 9) }}-\frac{\text{3 }}{\text{x^2 - 6x + 9 }}-\frac{\text{x}}{\text{x^2 - 9}}\)
g) \(\frac{\text{x + 2 }}{\text{x + 3 }}-\frac{\text{5 }}{\text{x^2 + x - 6 }}+\frac{\text{1}}{\text{2 - x}}\)
h) \(\frac{\text{4x }}{\text{x + 2 }}-\frac{\text{3x }}{\text{x - 2 }}+\frac{\text{12x}}{\text{x^2 - 4}}\)
i) \(\frac{\text{ x + 1 }}{\text{ x - 1 }}-\frac{\text{ x - 1 }}{\text{ x + 1 }}-\frac{\text{4}}{\text{1 - x^2}}\)
k) \(\frac{\text{
3x + 21
}}{\text{
x^2 - 9
}}+\frac{\text{2 }}{\text{x + 3 }}-\frac{\text{3}}{\text{x - 3}}\)
Cho A frac{text{1}}{text{6.10}}text{+}frac{text{1}}{text{7}text{.}text{9}}+ frac{text{1}}{text{8.8}}text{+}frac{text{1}}{text{9}text{.}text{7}}+frac{text{1}}{text{10.6}}CMR : A frac{text{1}}{text{8}}text{.}text{(}frac{text{1}}{text{6}}text{+}frac{text{1}}{text{7}}text{+}frac{text{1}}{text{8}}text{+}frac{text{1}}{text{9}}text{+}frac{text{1}}{text{1}text{0}}text{)} ai giúp mình nhanh mình cho hẳn 3 tick.:(
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Cho A = \(\frac{\text{1}}{\text{6.10}}\text{+}\frac{\text{1}}{\text{7}\text{.}\text{9}}\)+ \(\frac{\text{1}}{\text{8.8}}\text{+}\frac{\text{1}}{\text{9}\text{.}\text{7}}\)+\(\frac{\text{1}}{\text{10.6}}\)
CMR : A = \(\frac{\text{1}}{\text{8}}\text{.}\text{(}\frac{\text{1}}{\text{6}}\text{+}\frac{\text{1}}{\text{7}}\text{+}\frac{\text{1}}{\text{8}}\text{+}\frac{\text{1}}{\text{9}}\text{+}\frac{\text{1}}{\text{1}\text{0}}\text{)}\)
ai giúp mình nhanh mình cho hẳn 3 tick.:'(
Ai giải giúp mấy bài toán vsBài 1:Asqrt{frac{1}{text{√}2+1}-frac{text{√}8-text{√}10}{2-text{√}5}}Bfrac{5text{√}5}{text{√}5+2}+frac{text{√}5}{text{√}5-1}-frac{3text{√}5}{3+text{√}5}Bài 2 rút gọn biểu thứcAleft(frac{x+sqrt[]{xy}}{text{√}x+text{√}y}-2right):frac{1}{text{√}x+2} với x :y 0Bleft(frac{a}{a-2text{√}a}+frac{a}{text{√}a-2}right):frac{text{√}a+1}{a-4text{√}a+4}Bài 3 cho biểu thứcPleft(frac{x-2}{x+2text{√}x}+frac{1}{text{√}x+2}right)frac{text{√}x+1}{text{√}x-1}a)Rút gọn Pb)tìm x để Ptext{√}...
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Ai giải giúp mấy bài toán vs
Bài 1:
A=\(\sqrt{\frac{1}{\text{√}2+1}-\frac{\text{√}8-\text{√}10}{2-\text{√}5}}\)
B=\(\frac{5\text{√}5}{\text{√}5+2}+\frac{\text{√}5}{\text{√}5-1}-\frac{3\text{√}5}{3+\text{√}5}\)
Bài 2 rút gọn biểu thức
A=\(\left(\frac{x+\sqrt[]{xy}}{\text{√}x+\text{√}y}-2\right):\frac{1}{\text{√}x+2}\) với x :y >0
B=\(\left(\frac{a}{a-2\text{√}a}+\frac{a}{\text{√}a-2}\right):\frac{\text{√}a+1}{a-4\text{√}a+4}\)
Bài 3 cho biểu thức
P=\(\left(\frac{x-2}{x+2\text{√}x}+\frac{1}{\text{√}x+2}\right)\frac{\text{√}x+1}{\text{√}x-1}\)
a)Rút gọn P
b)tìm x để P=\(\text{√}x+\frac{5}{2}\)
bài 4 rút gọn biểu thức
A=\(\frac{1}{x+\text{√}x}+\frac{2\text{√}x}{x-1}-\frac{1}{x-\text{√}x}\)
B=\(\left(\frac{x}{x+3\text{√}x}+\frac{1}{\text{√}x+3}\right):\left(1-\frac{2}{\text{√}x}+\frac{6}{x+3\text{√}x}\right)\)
Bài 5
A=\(\left(\frac{2}{\text{√}x-3}-\frac{1}{\text{√}x+3}-\frac{x}{\text{√}x\left(x-9\right)}\right):\text{(√}x+3-\frac{x}{\text{√}x-3}\)
a)rút gọn A
b)tìm gtri x để A= -1/4
AI GIẢI GIÙM MÌNH ĐI MÌNH TẠ ƠN
Rút gọn :
a.text{3}sqrt{2}text{+ }4sqrt{text{8}}-sqrt{text{1}text{8}}
b.sqrt{text{3}}-frac{text{1}}{text{3}}sqrt{27}text{+ }2sqrt{text{5}07}
c.sqrt{2text{5}a}text{+ }sqrt{49a}-sqrt{text{6}4a}
d.-sqrt{text{3}text{6}b}text{−}frac{text{1}}{text{3}}sqrt{text{5}4b}text{+}frac{text{1}}{text{5}}sqrt{text{1}text{5}0b}
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Rút gọn :
a.\(\text{3}\sqrt{2}\text{+ }4\sqrt{\text{8}}-\sqrt{\text{1}\text{8}}\)
b.\(\sqrt{\text{3}}-\frac{\text{1}}{\text{3}}\sqrt{27}\text{+ }2\sqrt{\text{5}07}\)
c.\(\sqrt{2\text{5}a}\text{+ }\sqrt{49a}-\sqrt{\text{6}4a}\)
d.\(-\sqrt{\text{3}\text{6}b}\text{−}\frac{\text{1}}{\text{3}}\sqrt{\text{5}4b}\text{+}\frac{\text{1}}{\text{5}}\sqrt{\text{1}\text{5}0b}\)
a) Ta có: \(3\sqrt{2}+4\sqrt{8}-\sqrt{18}\)
\(=\sqrt{2}\left(3+4\cdot2-3\right)\)
\(=8\sqrt{2}\)
b) Ta có: \(\sqrt{3}-\frac{1}{3}\sqrt{27}+2\sqrt{507}\)
\(=\sqrt{3}\left(1-\frac{1}{3}\cdot\sqrt{9}+2\cdot\sqrt{169}\right)\)
\(=\sqrt{3}\left(1-1+26\right)\)
\(=26\sqrt{3}\)
c) Ta có: \(\sqrt{25a}+\sqrt{49a}-\sqrt{64a}\)
\(=\sqrt{25}\cdot\sqrt{a}+\sqrt{49}\cdot\sqrt{a}-\sqrt{64}\cdot\sqrt{a}\)
\(=\sqrt{a}\left(5+7-8\right)\)
\(=4\sqrt{a}\)
d) Ta có: \(-\sqrt{36b}-\frac{1}{3}\sqrt{54b}+\frac{1}{5}\sqrt{150b}\)
\(=-\sqrt{6b}\cdot\sqrt{6}-\frac{1}{3}\cdot\sqrt{6b}\cdot\sqrt{9}+\frac{1}{5}\cdot\sqrt{6b}\cdot\sqrt{25}\)
\(=-\sqrt{6b}\left(\sqrt{6}+1-1\right)\)
\(=-\sqrt{6b}\cdot\sqrt{6}=-6\sqrt{b}\)
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1. Một người làm từ 8 giờ đến 11 giờ thì xong 6 sản phẩm. Hỏi trung bình người đó làm 1 sản phẩm hết bao nhiêu thời gian
2) Điền số
\(\frac{1}{5}gi\text{ờ}=ph\text{út}=gi\text{â}y\)
\(2\frac{1}{4}ph\text{ú}t+\frac{1}{3}ph\text{ú}t=gi\text{â}y\)
Giải:
1) Thời gian người đó làm xong 6 sản phẩm là:
11 - 8 = 3 (giờ)
Thòi gian người đó làm một sản phẩm là:
3 : 6 = 0,5 (giờ)
=30 (phút)
Đáp số: 30 phút
2) 1/5 giờ = 12 phút = 720 giây
\(2\frac{1}{4}\) phút + \(\frac{1}{3}\) phút = 135 giây + 20 giây = 155 giây
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