19. (a-b)/d...a = -2, b = 3, c = 6 and d = 1/3
(-2 - 3) / (1/3) =
-5/(1/3) =
-5 * 3 = -15 <==
20. -a(b + c) =
-2(3 + 6) =
-2(9) =
-18 < ==
22. (a - b + 3d)/b
(-2 - 3 + 3(1/3) / 3 =
(-5 + 1)/3 =
-4/3 <===
23. b - a^2
3 - (-2^2) =
3 + 4 =
7 <===
25. ab^2 =
-2 * 3^2 =
-2 * 9 =
-18 <===
26. -(b-c)^2
- (3 - 6)^2 =
-(-3)^2 =
-9 <==
