a) $2x – (–17) = 15$
$⇔2x+17=15$
$⇔2x=-2$
$⇔x=-1$
b)$ x – 2 = -3$
$⇔x=-3+2$
$⇔x=-1$
c)$ 2x + 12 = 3(x – 7)$
$⇔2x+12=3x-21$
$⇔2x-3x=-21-12$
$⇔-x=-33$
$⇔x=33$
d) $2. ( x – 3) – 3. (x – 5) = 4. ( 3 – x) – 18$
$⇔2x-6-3x+15=12-4x-18$
$⇔2x-3x+4x=12-18+6-15$
$⇔3x=-15$
$⇔x=-5$
e) $– 2(2x – 8) + 3(4 – 2x) = -72 – 5(3x – 7)$
$⇔-4x+16+12-6x=-72-15x+35$
$⇔-4x-6x+15x=-72+35-16-12$
$⇔5x=-65$
$⇔x=-13$