Question

select values of a and b so that the equation $3(2x + 5) = (a + 2)x + b$ is an identity.
$a =$ select choice
$b =$ select choice

Explanation:

Step1: Expand left-hand side

$3(2x+5)=6x+15$

Step2: Equate coefficients of $x$

$6 = a + 2$
Solve for $a$: $a=6-2=4$

Step3: Equate constant terms

$15 = b$

Answer:

$a=4$, $b=15$