Question

Answer 1

a.

\(\dfrac{4}{5}-\dfrac{1}{2}x=\dfrac{1}{10}\)

\(\dfrac{1}{2}x=\dfrac{4}{5}-\dfrac{1}{10}\)

\(\dfrac{1}{2}x=\dfrac{7}{10}\)

\(x=\dfrac{7}{10}:\dfrac{1}{2}\)

\(x=\dfrac{7}{5}\)

Answer 2

b.

\(-\dfrac{2}{3}x+\dfrac{1}{5}=\dfrac{1}{10}\)

\(-\dfrac{2}{3}x=\dfrac{1}{10}-\dfrac{1}{5}\)

\(-\dfrac{2}{3}x=-\dfrac{1}{10}\)

\(x=\left(-\dfrac{1}{10}\right):\left(-\dfrac{2}{3}\right)\)

\(x=\dfrac{3}{20}\)

Answer 3

c.

\(\left(3\dfrac{1}{2}+2x\right).2\dfrac{2}{3}=5\dfrac{1}{3}\)

\(\left(\dfrac{7}{2}+2x\right).\dfrac{8}{3}=\dfrac{16}{3}\)

\(\dfrac{7}{2}+2x=\dfrac{16}{3}:\dfrac{8}{3}\)

\(\dfrac{7}{2}+2x=2\)

\(2x=2-\dfrac{7}{2}\)

\(2x=-\dfrac{3}{2}\)

\(x=-\dfrac{3}{2}:2\)

\(x=-\dfrac{3}{4}\)

Answer 4

d.

\(\left(\dfrac{2}{11}+\dfrac{1}{3}\right)x=\left(\dfrac{1}{7}-\dfrac{1}{8}\right).56\)

\(\left(\dfrac{6}{33}+\dfrac{11}{33}\right)x=\left(\dfrac{8}{56}-\dfrac{7}{56}\right).56\)

\(\dfrac{17}{33}x=\dfrac{1}{56}.56\)

\(\dfrac{17}{33}x=1\)

\(x=1:\dfrac{17}{33}\)

\(x=\dfrac{33}{17}\)

Answer 5

e.

\(\left(\dfrac{3}{4}x+2\dfrac{1}{2}\right)^2.\dfrac{-1}{2}=\dfrac{1}{-8}\)

\(\left(\dfrac{3}{4}x+\dfrac{5}{2}\right)^2=\dfrac{1}{-8}:\dfrac{-1}{2}\)

\(\left(\dfrac{3}{4}x+\dfrac{5}{2}\right)^2=\dfrac{1}{4}\)

\(\left(\dfrac{3}{4}x+\dfrac{5}{2}\right)^2=\left(\dfrac{1}{2}\right)^2\)

\(\dfrac{3}{4}x+\dfrac{5}{2}=\dfrac{1}{2}\) hoặc \(\dfrac{3}{4}x+\dfrac{5}{2}=-\dfrac{1}{2}\)

\(\dfrac{3}{4}x=\dfrac{1}{2}-\dfrac{5}{2}\) hoặc \(\dfrac{3}{4}x=-\dfrac{1}{2}-\dfrac{5}{2}\)

\(\dfrac{3}{4}x=-2\) hoặc \(\dfrac{3}{4}x=-3\)

\(x=-2:\dfrac{3}{4}\) hoặc \(x=-3:\dfrac{3}{4}\)

\(x=-\dfrac{8}{3}\) hoặc \(x=-4\)