Answer:
40. -8
42. 38
Explanation:
We are given these following values:
a = -2, b = 4, c = -8
We have to evaluate these following expressions:
40. ab
ab = a*b = (-2)*4 = -8
When two terms with different signals are multiplied, the answer is negative. 4*2 = 8. So the answer is -8.
42. -ab³-ac = -(-2)*(3)³ - (-2)*(-8) = -(-2)*(27) - (16) = -(-54) - 16 = 54 - 16 = 38