Answer:
C
Step-by-step explanation:
Expand the factors and compare the coefficients of like terms.
Given
(mx + 2)(3x - 5) ← expand using FOIL
= 3mx² - 5mx + 6x - 10
Compare to 12x² - 14x - 10
For the 2 to be equal, then the coefficients of like terms must be equal.
Compare coefficients of x² terms
3m = 12 ( divide both sides by 3 )
m = 4 → C
A conditional statement is always true backwards and forwards
A=12
120% of a =80% of b
120%a = 80%b
120a/100 = 80b/100
Divide through by 100
120a = 80b
Divide through by 80
120a/80 = b
But a=12
120x 12/80 = b
18 = b
b = 18
a+b = 12 + 18 = 30