Bài 1: Rút gọn rồi tính
a) \(\dfrac{22}{55}+\dfrac{25}{125}+\dfrac{1020}{5100}\)
b) \(\dfrac{22}{77}+\dfrac{56}{98}+\dfrac{25}{105}\)
(Các bạn giải chi tiết cho mình ạ!)
2. tính rồi rút gọn:
a) 22/55+25/125+1020/5100
b) 22/77+56/98+25/105
ai làm nhanh mình like cho
a. \(\frac{22}{55}\)+ \(\frac{25}{125}\)+ \(\frac{1020}{5100}\)
= \(\frac{2}{5}\)+ \(\frac{1}{5}\)+ \(\frac{1}{5}\)
= \(\frac{4}{5}\)
B. \(\frac{22}{77}\)+ \(\frac{56}{98}\)+ \(\frac{25}{105}\)
= \(\frac{2}{7}\)+ \(\frac{4}{7}\)+ \(\frac{5}{21}\)
= \(\frac{6}{7}\)+ \(\frac{5}{21}\)
= \(\frac{23}{21}\)
23/21 bn nhé
ai lớp 4 hoặc 5 kb mik nhé mik luôn sẵn sàng
= 23 | 21 nhé bạn
Rút gọn rồi tính
a) 22/25 + 25/125 + 36/96
b) 22/77 + 56/98 + 25/105
a)\(\dfrac{22}{25}+\dfrac{25}{125}+\dfrac{36}{96}\)
\(=\dfrac{22}{25}+\dfrac{1}{5}+\dfrac{3}{8}\)
\(=\dfrac{176}{200}+\dfrac{40}{200}+\dfrac{75}{200}\)
\(=\dfrac{291}{200}\)
b)\(\dfrac{22}{77}+\dfrac{56}{98}+\dfrac{25}{105}\)
\(=\dfrac{2}{7}+\dfrac{4}{7}+\dfrac{5}{21}\)
\(=\dfrac{6}{7}+\dfrac{5}{21}\)
\(=\dfrac{18}{21}+\dfrac{5}{21}=\dfrac{23}{21}\)
rút gọn biểu thức sau
A=\(\left(\dfrac{15-\sqrt{x}}{x-25}+\dfrac{2}{\sqrt{x}+5}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\)
giải chi tiết hộ mình với ạ !!!
\(A=\left(\dfrac{15-\sqrt{x}}{x-25}+\dfrac{2}{\sqrt{x}+5}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\)
\(=\dfrac{15-\sqrt{x}+2\sqrt{x}-10}{\left(\sqrt{x}+5\right)\left(\sqrt{x}-5\right)}\cdot\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\)
\(=\dfrac{1}{\sqrt{x}+1}\)
\(A=\left(\dfrac{15-\sqrt{x}}{x-25}+\dfrac{2}{\sqrt{x}+5}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\left(x\ge0;x\ne25\right)\\ A=\dfrac{15-\sqrt{x}+2\left(\sqrt{x}-5\right)}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\cdot\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\\ A=\dfrac{5+\sqrt{x}}{\sqrt{x}+5}\cdot\dfrac{1}{\sqrt{x}+1}=\dfrac{1}{\sqrt{x}+1}\)
Rút gọn biểu thức sau
C=\(\left(\dfrac{15-\sqrt{x}}{x-25}+\dfrac{2}{\sqrt{x}+5}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\)
giải chi tiết hộ mình vs ạ
\(C=\left(\dfrac{15-\sqrt{x}}{x-25}+\dfrac{2}{\sqrt{x}+5}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\left(đk:x\ge0,x\ne25\right)\)
\(=\dfrac{15-\sqrt{x}+2\left(\sqrt{x}-5\right)}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}.\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\)
\(=\dfrac{\sqrt{x}+5}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}.\dfrac{\sqrt{x}-5}{\sqrt{x}+1}=\dfrac{1}{\sqrt{x}+1}\)
\(ĐK:x\ge0;x\ne25\)
\(C=\dfrac{15-\sqrt{x}+2\sqrt{x}-10}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\cdot\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\\ C=\dfrac{\sqrt{x}+5}{\left(\sqrt{x}+5\right)\left(\sqrt{x}+1\right)}=\dfrac{1}{\sqrt{x}+1}\)
DKXD: \(x\ne5;x>0\)
\(C=\left(\dfrac{15-\sqrt[]{x}}{x-25}+\dfrac{2}{\sqrt[]{x}+5}\right):\dfrac{\sqrt[]{x+1}}{\sqrt[]{x}-5}\)
\(C=\left(\dfrac{15-\sqrt[]{x}}{\left(\sqrt[]{x}—5\right)\left(\sqrt{x}+5\right)}+\dfrac{2\left(\sqrt[]{x}-5\right)}{\left(\sqrt[]{x}-5\right)\left(\sqrt{x+5}\right)}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}-5}\)
\(C=\left(\dfrac{15-\sqrt{x}+2\sqrt{x}-10}{\left(\sqrt{x}+5\right)\left(\sqrt{x}-5\right)}\right).\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\)
\(C=\dfrac{5+\sqrt{x}}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}.\dfrac{\sqrt{x}-5}{\sqrt{x}+1}\)
\(C=\dfrac{1}{\sqrt{x}+1}\)
cho mình hỏi bài này với a: tìm các số tự nhiên x biết
x/7=22/77
\(\dfrac{x}{7}=\dfrac{22}{77}\)\(_{_{ }_{ }^{ }\dfrac{x}{7}=\dfrac{22}{77}}\)
`x/7 = 22/77`
`=>77x= 22.7`
`=>77x= 154`
`=>x=154:77`
`=>x=2`
Rút gọn về phân số tối giản:
a) \(\dfrac{56}{70}\) b) \(\dfrac{-120}{86}\)
c) \(\dfrac{915+85}{1017-117}\) c) \(\dfrac{3838}{5454}\)
*Lưu ý: Các bạn viết đáp án chi tiết cho mình nha! :333
a)\(\dfrac{56}{70}=\dfrac{56:14}{70:14}=\dfrac{4}{5}\)
b)\(\dfrac{-120}{86}=\dfrac{-120:2}{86:2}=-\dfrac{60}{43}\)
c)\(\dfrac{915+85}{1017-117}=\dfrac{1000}{900}=\dfrac{10}{9}\)
d)\(\dfrac{3838}{5454}=\dfrac{19}{27}\)
a) \(\dfrac{56}{70}=\dfrac{4}{5}\)
\(b,-\dfrac{120}{86}=-\dfrac{60}{43}\)
\(c,\dfrac{10}{9}\)
\(d,\dfrac{19}{27}\)
\(\dfrac{-5}{17}\) x \(\dfrac{11}{25}\) + \(\dfrac{-5}{17}\) x \(\dfrac{26}{25}\) - \(\dfrac{-5}{17}\) x \(\dfrac{3}{25}\)
Các bạn giải chi tiết dùm mình nha, tks
Tính hợp lí ( nếu có thể)
\(P=\dfrac{32}{19}.\dfrac{-57}{64}+\dfrac{35}{-44}.\dfrac{-22}{21}\)
\(Q=\dfrac{75}{164}.\dfrac{82}{125}-\dfrac{49}{-105}.\dfrac{-35}{98}\)
\(P=\dfrac{32}{64}\cdot\dfrac{-57}{19}+\dfrac{35}{21}\cdot\dfrac{22}{44}=\dfrac{1}{2}\left(-3+\dfrac{5}{3}\right)=\dfrac{1}{2}\cdot\dfrac{-4}{3}=\dfrac{-2}{3}\)
\(Q=\dfrac{75}{125}\cdot\dfrac{82}{164}+\dfrac{49}{98}\cdot\dfrac{-35}{105}=\dfrac{1}{2}\left(\dfrac{3}{5}-\dfrac{1}{3}\right)=\dfrac{1}{2}\cdot\dfrac{4}{15}=\dfrac{2}{15}\)
Tính: \(\dfrac{5}{12}+\dfrac{5}{20}+\dfrac{5}{30}+\dfrac{5}{42}+\dfrac{5}{56}\)
CÁC BẠN GIẢI CHI TIẾT BÀI NÀY GIÚP MÌNH NHÉ! CẢM ƠN CÁC BẠN RẤT NHIỀU! 🤧🙏💖
\(=5\left(\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+\dfrac{1}{56}\right)\)
\(=5\left(\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+...+\dfrac{1}{7}-\dfrac{1}{8}\right)\)
\(=5\cdot\dfrac{5}{24}=\dfrac{25}{24}\)
`5/12 + 5/20 + 5/30 + 5/42 + 5/56`
`= 5/(3.4) + 5/(4.5) + 5/(5.6) + 5/(6.7) + 5/(7.8)`
`= 5 . (1/(3.4) + 1/(4.5) + ... + 5/(7.8))`
`= 5 . (1/3 - 1/4 + 1/4 - 1/5 + ...+ 1/7 - 1/8)`
`= 5 . (1/3 - 1/8) `
`= 5 . 5/24 = 25/24`