Question

Tìm x, biết:

a, 2(x - 5) - 3(x + 7) = 14

b, 5(x - 6) - 2(x + 3) = 12

c, -7(5 - x) - 2(x - 10) = 15

d, 4(x - 1) - 3(x - 2) = -(- 5)

e, 7(x - 9) - 5(6 - x) = (- 6) + 11x

Answer 1

\(a,2\left(x-5\right)-3\left(x+7\right)=14\)

\(\Leftrightarrow2x-10-3x-21=14\)

\(\Leftrightarrow-x-31=14\Leftrightarrow-x=45\Leftrightarrow x=-45\)

\(c,5\left(x-6\right)-2\left(x+3\right)=12\)

\(\Leftrightarrow5x-30-2x-6=12\)

\(\Leftrightarrow3x-36=12\Leftrightarrow3x=48\Leftrightarrow x=16\)

Các câu còn lại tương tự 

Answer 2

a, 2(x - 5) - 3(x + 7) = 14\(\Rightarrow2\chi-10-3\chi+21=14\Rightarrow2\chi-3\chi=14+10-21\)

\(\Rightarrow-\chi=3\Rightarrow\chi=3\)