Verified answer

а) 2 * (х + 3) = 2 * х + 2 * 3 = 2х + 6;

б) (5 + а) * 4 = 5 * 4 + а * 4 = 20 + 4а;

в) (8 - у) * 6 = 8 * 6 - у * 6 = 48 - 6у;

г) 3 * (12 - b) = 3 * 12 - 3 * b = 36 - 3b.