Answer:  a = 12 or in decimal a= 0.5

Step-by-step explanation:implify the left side.

2a + 7 = 9 - 2a

Move all terms containing

a

to the left side of the equation.

4a + 7 = 9

Move all terms not containing

a

to the right side of the equation.

4a = 2

Divide each term by

4

and simplify.

a = 1/2

and then you get your answer provided up top or here

Exact form : a = 1/2  

Decimal Form : a = 0.5