\(a.\left(2,8x-32\right):\frac{2}{3}=-90\)
\(2,8x-32=-90\cdot\frac{2}{3}=-30\cdot\frac{2}{1}\)
\(2,8x-32=-60\)
\(2,8x=-60+32\)
\(2,8x=28\)
\(x=\frac{28}{2,8}=10\). Vậy x=10
\(b.\left(4,5-2x\right)\cdot1\frac{4}{7}=\frac{11}{14}\)
\(4,5-2x=\frac{11}{14}:\frac{11}{7}=\frac{11}{14}\cdot\frac{7}{11}\)
\(4,5-2x=\frac{1}{2}\)
\(2x=\frac{45}{10}-\frac{1}{2}=\frac{9}{2}-\frac{1}{2}=\frac{8}{2}\)
\(2x=4\)
\(x=\frac{4}{2}=2\) . Vậy x=2
Chúc bạn học tốt!^_^
a)(2,8x-32):\(\frac{2}{3}\)=-90
(2,8x-32) =(-90).\(\frac{2}{3}\)
(2,8x-32) =(-60)
2,8x =(-60)+32
2,8x =(-28)
x =(-28):2,8
x =(-10)
b)(4,5-2x).1\(\frac{4}{7}\)=\(\frac{11}{14}\)
(4,5-2x).\(\frac{11}{7}\)=\(\frac{11}{14}\)
(4,5-2x) =\(\frac{11}{14}\):\(\frac{11}{7}\)
(4,5-2x) =\(\frac{1}{2}\)
2x =4,5-\(\frac{1}{2}\)
2x =4
x =4:2
x =2
Bạn kia sai rồi
-60+32 mà bằng 28 đáng ra phải là -28 chứ bạn tính lại đi bạn tôi học giỏi toán
\(a)\left(2,8x-32\right):\frac{3}{2}=-90\)
\(\Leftrightarrow2,8x-32=-60\)
\(\Leftrightarrow2,8x=28\)
\(\Leftrightarrow x=\frac{28}{2,8}=10\)
\(b)\left(4,5-2x\right)x1\frac{4}{7}=\frac{11}{14}\)
\(\Leftrightarrow4,5-2x=\frac{1}{2}\)
\(\Leftrightarrow2x=4\)
\(\Leftrightarrow x=2\)
\(\left(2,8x-32\right)\div\frac{2}{3}=-90\)
<=> \(2,8x-32=-60\)
<=> \(2,8x=-28\)
<=> \(x=-10\)
\(\left(4,5-2x\right)\cdot1\frac{4}{7}=\frac{11}{14}\)
<=> \(4,5-2x=\frac{1}{2}\)
<=> \(2x=4\)
<=> \(x=2\)
\(a)\)\(\left(2,8x-32\right):\frac{2}{3}=-90\)
\(\Leftrightarrow2,8x-32=-60\)
\(\Leftrightarrow2,8x=-28\)
\(\Leftrightarrow x=-10\)
Vậy\(x=-10\)
\(b)\)\(\left(4,5-2x\right).1\frac{4}{7}=\frac{11}{14}\)
\(\Leftrightarrow\left(4,5-2x\right).\frac{11}{7}=\frac{11}{14}\)
\(\Leftrightarrow4,5-2x=\frac{11}{14}:\frac{11}{7}\)
\(\Leftrightarrow4,5-2x=\frac{11}{14}.\frac{7}{11}\)
\(\Leftrightarrow4,5-2x=0,5\)
\(\Leftrightarrow2x=4\)
\(\Leftrightarrow x=2\)
Vậy\(x=2\)
Linz
