Explanation

This question provides us an equation involving 2 variables, but also provides us the value of one of those variables. By substituting the known variable value into the second equation, we can use algebraic manipulation to solve for the unknown variable a.

When we substitute the value of n into the equation, we get 5a=7(5)+5 5a=40

Dividing both sides by 5 gives a = 8.

**The correct answer is (E).**

When we substitute the value of n into the equation, we get 5a=7(5)+5 5a=40

Dividing both sides by 5 gives a = 8.