1) 7(0.5+1) + 1.5 - 9
= 7(1.5) + 1.5 - 9
= 10.5 + 1.5 - 9
= 12 - 9
= 3

2) -0.9(6-5a) + 2.5a + 12
= -0.9(6) - (-0.9)(5a) + 2.5a + 12
= -5.4 + 4.5a + 2.5a + 12
= 7a - 5.4 + 12
= 7a + 6.6