Answer:
18x² - 3x - 10
Explanation:
 a = 3x + 2
 b = -5 +6x
To find ab use FOIL method.
ab = (3x + 2) (-5 + 6x)
 = 3x *(-5) + 3x*6x + 2*(-5) + 2*6x
 = -15x + 18x² - 10 + 12x
 = 18x² - 15x + 12x - 10
Combine co-efficient of like terms. Like terms have same variable with same power. Here, (-15x) and 12x are like terms.
 = 18x² - 3x - 10