Question

What does 4a+(9a+3) equal

Answer 1

4a+(9a+3)=0
4a+9a+3=0
13a+3=0
13a=-3
a=-3/13
a=-0.23

Answer 2

im assuming this equation is set equal to 0 because you gave no indication of what it is set to.
4a+1(9a+3)=0
4a+9a+3
13a=-3
a=-3/13