Câu 1.Tính:
1\(\dfrac{7}{20}:2,7+2,7:1,35\)
b)3\(\dfrac{1}{2}-\)(0,4:2\(\dfrac{1}{2}\)).(4,2-1\(\dfrac{3}{4}\))
Thực hiện phép tính:
\(1\dfrac{7}{20}\):2,7+2,7:1,35+(0,4:\(2\dfrac{1}{2}\)).(4,2-\(1\dfrac{3}{40}\))
\(1\dfrac{7}{20}\div2,7+2,7\div1,35+\left(0,4\div2\dfrac{1}{2}\right)\times\left(4,2-1\dfrac{3}{40}\right)\)
\(=\dfrac{27}{20}\div\dfrac{27}{10}+\dfrac{27}{10}\div\dfrac{27}{20}+\left(\dfrac{2}{5}\div\dfrac{5}{2}\right)\times\left(\dfrac{21}{5}-\dfrac{43}{40}\right)\)
\(=\dfrac{27}{20}\times\dfrac{10}{27}+\dfrac{27}{10}\times\dfrac{20}{27}+\left(\dfrac{2}{5}\times\dfrac{2}{5}\right)\times\dfrac{25}{8}\)
\(=\dfrac{1}{2}+2+\dfrac{4}{25}\times\dfrac{25}{8}\)
\(=\dfrac{5}{2}+\dfrac{1}{2}\)
\(=3\)
Tính
a, \(1\dfrac{7}{20}\) : 2,7+2,7:1,35+(0,4:\(2\dfrac{1}{2}\) ) . (4,2-\(1\dfrac{3}{40}\) )
b, \(\left(6\dfrac{3}{5}-3\dfrac{3}{14}\right).5\dfrac{5}{6}:\left(21-1.25\right):2,5\)
c,\(\dfrac{0,125-\dfrac{1}{5}+\dfrac{1}{7}}{0,375-\dfrac{3}{5}+\dfrac{3}{7}}+\dfrac{\dfrac{1}{2}+\dfrac{1}{3}-0,2}{\dfrac{3}{4}+0,5-\dfrac{3}{10}}\)
a) \(1\dfrac{7}{20}:2,7+2,7:1,35+\left(0,4:2\dfrac{1}{2}\right).\left(4,2-1\dfrac{3}{40}\right)\)
\(=\dfrac{27}{20}:\dfrac{27}{10}+\dfrac{27}{10}:\dfrac{27}{10}+\left(\dfrac{2}{5}:\dfrac{5}{2}\right).\left(\dfrac{21}{5}-\dfrac{43}{40}\right)\)
\(=1+1+\dfrac{4}{25}.\dfrac{25}{8}\)
\(=2+\dfrac{1}{2}\)
\(=2\dfrac{1}{2}\)
b) \(\left(6\dfrac{3}{5}-3\dfrac{3}{14}\right).5\dfrac{5}{6}:\left(21-1.25\right):2,5\)
\(=\left(\dfrac{33}{5}-\dfrac{45}{14}\right).\dfrac{35}{6}:\left(-4\right):2,5\)
\(=\left(\dfrac{462}{60}-\dfrac{225}{60}\right).\dfrac{35}{6}.\dfrac{1}{-4}:\dfrac{5}{2}\)
\(=\dfrac{237}{60}.\dfrac{35}{6}.\dfrac{1}{-4}.\dfrac{2}{5}\)
\(=\dfrac{3.79.7.5.2}{5.14.3.2.\left(-4\right).5}\)
\(=\dfrac{79.7}{14.\left(-4\right).5}=\dfrac{553}{-280}\) (số xấu :v)
c) \(\dfrac{0,125-\dfrac{1}{5}+\dfrac{1}{7}}{0,375-\dfrac{3}{5}+\dfrac{3}{7}}+\dfrac{\dfrac{1}{2}+\dfrac{1}{3}-0,2}{\dfrac{3}{4}+0,5-\dfrac{3}{10}}\)
\(=\dfrac{0,125-\dfrac{1}{5}+\dfrac{1}{7}}{3\left(0,125-\dfrac{1}{5}+\dfrac{1}{7}\right)}+\dfrac{\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{5}}{\dfrac{3}{4}+\dfrac{1}{2}-\dfrac{3}{10}}\)
\(=\dfrac{1}{3}+\dfrac{\dfrac{30}{60}+\dfrac{20}{60}-\dfrac{12}{60}}{\dfrac{45}{60}+\dfrac{30}{60}-\dfrac{9}{60}}\)
\(=\dfrac{1}{3}+\dfrac{\dfrac{19}{30}}{\dfrac{11}{10}}\)
\(=\dfrac{1}{3}+\dfrac{19}{33}\)
\(=\dfrac{11}{33}+\dfrac{19}{33}=\dfrac{30}{33}=\dfrac{10}{11}\)
Bài 1.Tính hợp lí:
a) -15,5 . 20,8+3,5 . 9,2-15,5 . 9,2+3,5 . 20,8
b) \(1\dfrac{1}{20}:2,7+2,7:1,35+\left(0,4:2\dfrac{1}{2}\right).\left(4,2-1\dfrac{3}{10}\right)\)
a: \(=-15,5\left(20,8+9,2\right)+3,5\left(9,2+20,8\right)\)
\(=30\cdot\left(-12\right)=-360\)
b: \(=\dfrac{21}{20}:\dfrac{27}{10}+2+\left(\dfrac{2}{5}:\dfrac{5}{2}\right)\cdot\left(\dfrac{21}{5}-\dfrac{13}{10}\right)\)
\(=\dfrac{21}{10}\cdot\dfrac{10}{27}+2+\dfrac{4}{25}\cdot\dfrac{29}{10}\)
\(=\dfrac{7}{9}+2+\dfrac{58}{125}=\dfrac{3647}{1125}\)
1 7/20: 2,7+2,7:1,35+(0,4:2 1/2).(4,2-1 3/40)=
\(B=1.\frac{7}{20}:2,7+2,7:1,35+\left(0,4+2\frac{1}{2}\right)\times\left(4,2-1\frac{3}{10}\right)\)
giải rỏ ràng dùm minh nha
\(B=1x\frac{7}{20}:2,7+2,7:1,35+\left(0,4+2\frac{1}{2}\right)x\left(4,2-1\frac{3}{10}\right)\)
\(B=\frac{7}{20}:2,7+2+2,9x2,9\)
\(B=\frac{7}{54}+2+8,41\)
\(B=10,53962963\)
Bài 1:Tìm x
a, \(\dfrac{x}{6}=\dfrac{7}{3}\)
b,\(\dfrac{20}{x}=\dfrac{-12}{15}\)
c,\(\dfrac{-15}{35}=\dfrac{27}{x}\)
d,\(\dfrac{\dfrac{4}{5}}{1\dfrac{2}{5}}=\dfrac{2\dfrac{2}{5}}{x}\)
e,\(\dfrac{x}{1\dfrac{1}{4}}=\dfrac{1\dfrac{1}{5}}{2}\)
f,\(\dfrac{\dfrac{1}{2}}{1\dfrac{1}{4}}=\dfrac{x}{3\dfrac{1}{3}}\)
Bài 2:Tìm x
a,\(3x:2,7=\dfrac{1}{3}:2\dfrac{1}{4}\)
b,\(3:0,4x=1:0,01\)
c,\(4,5:0,3=2,25:0,1x\)
d,\(x:27=-2:3,6\)
Bài 3:Tìm x
a,\(1,35:0,2=1,25:0,1x\)
b,\(3,8:2x=\dfrac{1}{4}:2\dfrac{2}{3}\)
c,\(3\dfrac{1}{3}:2,4=0,35x:0,35\)
d,\(1\dfrac{1}{3}:0,8=\dfrac{2}{3}:0,1x\)
GIÚP MÌNH VỚI NHA
\(a,\dfrac{x}{6}=\dfrac{7}{3}\Rightarrow x=\dfrac{6.7}{3}\Rightarrow x=14\)
\(b,\dfrac{20}{x}=\dfrac{-12}{15}\Rightarrow x=\dfrac{20.15}{-12}\Rightarrow x=-25\)
\(c,\dfrac{-15}{35}=\dfrac{27}{x}\Rightarrow x=\dfrac{35.27}{-15}\Rightarrow x=-63\)
\(d,\dfrac{\dfrac{4}{5}}{1\dfrac{2}{5}}=\dfrac{2\dfrac{2}{5}}{x}\Rightarrow\dfrac{\dfrac{4}{5}}{\dfrac{7}{5}}=\dfrac{\dfrac{12}{5}}{x}\Rightarrow x=\dfrac{\dfrac{7}{5}.\dfrac{12}{5}}{\dfrac{4}{5}}\Rightarrow x=\dfrac{\dfrac{84}{25}}{\dfrac{4}{5}}\Rightarrow x=\dfrac{21}{5}\)
\(e,\dfrac{x}{1\dfrac{1}{4}}=\dfrac{5}{2}\Rightarrow\dfrac{x}{\dfrac{5}{4}}=\dfrac{5}{2}\Rightarrow x=\dfrac{5}{2}.\dfrac{5}{4}\Rightarrow x=\dfrac{25}{8}\)
\(f,\dfrac{\dfrac{1}{2}}{1\dfrac{1}{4}}=\dfrac{x}{3\dfrac{1}{3}}\Rightarrow\dfrac{\dfrac{1}{2}}{\dfrac{5}{4}}=\dfrac{x}{\dfrac{10}{3}}\Rightarrow x=\dfrac{\dfrac{10}{3}.\dfrac{1}{2}}{\dfrac{5}{4}}\Rightarrow x=\dfrac{\dfrac{5}{3}}{\dfrac{5}{4}}\Rightarrow x=\dfrac{4}{3}\)
a,\(1.25:0.2=1.25:0.1x\Rightarrow1.25:0.1x=\dfrac{25}{4}\Rightarrow0.1x=\dfrac{1}{5}\Rightarrow x=2\)
b,\(3.8:2x=\dfrac{1}{4}:2\dfrac{2}{3}\Rightarrow3.8:2x=\dfrac{3}{32}\Rightarrow2x=\dfrac{608}{15}\Rightarrow x=\dfrac{304}{15}\)
\(a,3x:2,7=\dfrac{1}{3}:2\dfrac{1}{4}\Rightarrow3x:2,7=\dfrac{4}{27}\Rightarrow3x=\dfrac{2}{5}\Rightarrow x=\dfrac{2}{15}\)
b,\(3:0.4x=1:0.01\Rightarrow3:0.4x=100\Rightarrow0.4x=\dfrac{3}{100}\Rightarrow x=\dfrac{3}{40}\)
c,
\(4,5:0,3=2,25:0.1x\Rightarrow2.25:0.1x=15\Rightarrow0.1x=\dfrac{3}{20}\Rightarrow x=\dfrac{3}{2}\)
d,\(x:27=-2:3,6\Rightarrow x:27=\dfrac{-5}{9}\Rightarrow x=-15\)
Bài 1:Tìm x
a, \(\dfrac{x}{6}=\dfrac{7}{3}\)
b,\(\dfrac{20}{x}=\dfrac{-12}{15}\)
c,\(\dfrac{-15}{35}=\dfrac{27}{x}\)
d,\(\dfrac{\dfrac{4}{5}}{1\dfrac{2}{5}}=\dfrac{2\dfrac{2}{5}}{x}\)
e,\(\dfrac{x}{1\dfrac{1}{4}}=\dfrac{1\dfrac{1}{5}}{2}\)
f,\(\dfrac{\dfrac{1}{2}}{1\dfrac{1}{4}}=\dfrac{x}{3\dfrac{1}{3}}\)
Bài 2:Tìm x
a,\(3x:2,7=\dfrac{1}{3}:2\dfrac{1}{4}\)
b,\(3:0,4x=1:0,01\)
c,\(4,5:0,3=2,25:0,1x\)
d,\(x:27=-2:3,6\)
Bài 3:Tìm x
a,\(1,35:0,2=1,25:0,1x\)
b,\(3,8:2x=\dfrac{1}{4}:2\dfrac{2}{3}\)
c,\(3\dfrac{1}{3}:2,4=0,35x:0,35\)
d,\(1\dfrac{1}{3}:0,8=\dfrac{2}{3}:0,1x\)
GIÚP MÌNH VỚI NHA
1)
a) \(\frac{x}{6}\)= \(\frac{7}{3}\)
\(\Rightarrow\)x.3=6.7
\(\Rightarrow\)x.3=42
\(\Rightarrow\)x =42:3
\(\Rightarrow\)x =14
b) làm tương tự như câu a
c) làm tương tự như câu
d) làm tương tư như câu a nhưng hơi phúc tạp một chút là bn phải đổi ra từ hỗn số ra phân số hoặc số nguyên
e) tương tự câu d
f) làm tương tự như câu d
2)
a) 3x:\(\frac{27}{10}\)=\(\frac{1}{3}\): \(2\frac{1}{4}\)
3x: \(\frac{27}{10}\) = \(\frac{1}{3}\): \(\frac{9}{4}\)
3x: \(\frac{27}{10}\) = \(\frac{4}{27}\)
3x = \(\frac{4}{27}\). \(\frac{27}{10}\)
3x = \(\frac{2}{5}\)
x = \(\frac{2}{5}\): 3
x = \(\frac{2}{15}\)
Các câu còn lại bn làm tương tự như câu a nha
3)
Làm tương tự như bài 2 nha
mik khuyên bn nếu bn giải bài thì bn nên đổi ra cùng một kiểu số thì tốt hơn như số số thập phân thì thập phân hết ấy
Cuối cùng chúc bn học giỏi
Tính bằng cách hợp lí giá trị của biểu thức.
A = \(\left(3-\dfrac{1}{4} +\dfrac{3}{2}\right)\)- \(\left(5+\dfrac{1}{3}-\dfrac{5}{6}\right)\)-\(\left(6-\dfrac{7}{4}+\dfrac{3}{2}\right)\)
B =\(0,5+\dfrac{1}{3}+0,4+\dfrac{5}{7}+\dfrac{1}{6}-\dfrac{4}{35}+\dfrac{1}{41}\)
\(A=\left(3-\dfrac{1}{4}+\dfrac{3}{2}\right)-\left(5+\dfrac{1}{3}-\dfrac{5}{6}\right)-\left(6-\dfrac{7}{4}+\dfrac{2}{3}\right)\\ \Rightarrow A=3-\dfrac{1}{4}+\dfrac{3}{2}-5-\dfrac{1}{3}+\dfrac{5}{6}-6+\dfrac{7}{4}-\dfrac{2}{3}\\ \Rightarrow A=\left(3-5-6\right)-\left(\dfrac{1}{4}+\dfrac{7}{4}\right)+\left(\dfrac{3}{2}+\dfrac{5}{6}-\dfrac{2}{3}\right)\\ \Rightarrow A=-8-\dfrac{3}{2}+\dfrac{5}{3}\\ =-\dfrac{47}{6}.\\ B=0,5+\dfrac{1}{3}+0,4+\dfrac{5}{7}+\dfrac{1}{6}-\dfrac{4}{35}+\dfrac{1}{41}\)
\(\Rightarrow B=\left(0,5+0,4\right)+\left(\dfrac{1}{3}+\dfrac{1}{6}\right)+\left(\dfrac{5}{7}-\dfrac{4}{35}\right)+\dfrac{1}{41}\\ \Rightarrow B=\dfrac{9}{10}+\dfrac{1}{2}+\dfrac{3}{5}+\dfrac{1}{41}\\ \Rightarrow B=2+\dfrac{1}{41}\\ \Rightarrow B=\dfrac{83}{41}.\)
Hỏi mấy câu nè:
-2\(\dfrac{1}{2}\) của 1,8 là:
A. -4,5 B. 4,5 C.2,7 D.-2,7
Kết quả phép tính \(\dfrac{8}{11}\) của -5 bằng:
A. \(\dfrac{-40}{55}\) B. \(\dfrac{-8}{55}\) C. \(\dfrac{-40}{11}\) D. \(\dfrac{-55}{8}\)
Một quả dưa hấu nặng 2kg.Vậy \(\dfrac{1}{4}\) quả dưa nặng bao nhiêu kg?
Kết quả phép tính 1,3+3,4-4,7+5,6-4,3
Trả lời nhanh Linh tick cho nkaa
Câu 1: A
Câu 2: C
Câu 3: 1/4 quả dưa nặng 0,5kg
Câu 4: =-3-1,3+5,6=4,3-3=1,3