Answer:
a = 1, b = - 3
Step-by-step explanation:
Expand the factors on the left side, then compare the coefficients of like terms on both sides.
left side
(ax + 4)(2x + b) ← expand using FOIL
= 2ax² + abx +8x + 4b
= 2ax² + x(ab + 8) + 4b
Compare coefficients of like terms with those on right side.
coefficients of x² terms
2a = 2 ( divide both sides by 2 )
a = 1
comparing constant terms
4b = - 12 ( divide both sides by 4 )
b = - 3
