Answer:
a = 51 , b = - 7
Explanation:
Expand and simplify left side , then compare like terms on both sides.
4(9x + 11) + 5(3x + b) ← distribute parenthesis
= 36x + 44 + 15x + 5b ← collect like terms
= 51x + 5b + 44
Compare terms with right side ax + 9
Compare x - terms
51x and ax
For these terms to be equal then
a = 51
Compare constant terms
5b + 44 and 9
For these terms to be equal , then
5b + 44 = 9 ( subtract 44 from both sides )
5b = - 35 ( divide both sides by 5 )
b = - 7