a) $(-3)^{2}$ - (3-x) = -12
⇔ 9 - (3 - x) = -12
⇔ 3 - x = 9 - (-12)
⇔ 3 - x = 9+12
⇔ 3- x = 21
⇔ x = 3-21
⇔ x = -18
b) -2(x +1/2 ) = -8/5
⇔ x + 1/2 = -8/5 ÷ (-2)
⇔ x + 1/2 = -4/5
⇔ x = -4/5 - 1/2
⇔ x = -13/10
c) (x+1) ÷ 2/3 = -2$\frac{1}{3}$
⇔ (x+1) ÷ 2/3 = $\frac{-7}{3}$
⇔ x +1 = -7/3 × 2/3
⇔ x + 1 = -14/9
⇔ x = -14/9 -1
⇔ x = -23/9
d) ⇔ (-37/12) × x = 5/24
⇔ x = 5/24 ÷ (-37/12)
⇔ x = -5/74
e)⇔ ( 13/3 + 3x )× 13/5 = 39/5
⇔ 13/3 + 3x = 3
⇔ 3x = 3 -13/3
⇔ 3x = -4/3
⇔ x = -4/3 ÷ 3
⇔ x = -4/9
f) ⇔(14/5)x - 32 = (-90) × 2/3
⇔ (14/5)x -32 = -60
⇔ (14/5)x = -60 +32
⇔ (14/5)x = -28
⇔ x = -10
