a) 2(x + 3) – 5 = 17 - x
⇔ 2x + 6 - 5 = 17 - x
⇔2x + x = -6 +5 + 17
⇔ 3x =16
⇔ x = $\frac{16}{3}$
b) 4( 3 + 2x) +1 = 5x + 3
⇔ 12 + 8x + 1 = 5x + 3
⇔ 8x - 5x = -12 -1 + 3
⇔ 3x = -10
⇔$\frac{-10}{3}$
c) 9x – 2(6 + 5x) = 7x – 3
⇔ 9x - 12 - 10x = 7x -3
⇔ 9x - 10x -7x = 12-3
⇔ -8x = 9
⇔x = $\frac{-9}{8}$
d) (3x – 1 ) (x + 3) = ( 2 – x) (5 – 3x)
⇔ 3x² + 6x - x - 3 = 10 - 6x - 5x + 3x²
⇔3x² - 3x² + 6x + 6x + 5x -x = 3 + 10
⇔ 19x =13
⇔ x =$\frac{13}{19}$
e) (x + 1) (x²-x+1) – 2x = x (x - 1)(x +1)
⇔ x³ - x² + x + x² - x + 1 -2x = (x² - x )( x + 1)
⇔ x³ - 2x + 1 = x³ + x² - x² -x
⇔ x³ - 2x - x³ - x² + x² + x = -1
⇔ -x = -1
⇔ x = 1