Answer:
a = 5
Step-by-step explanation:
If it's easier for you, you can replace n(a) with y and put a as x.
Now the equation is y = 7x + 4.
It asks you to put in 39 as y.
39 = 7x + 4.
To solve this, the goal is to isolate the variable on one side. The first step I see is to subtract the 4 from both sides.
35 = 7x
Now divide both sides by 7 and we're done!
5 = x
