Which value of a below solves the equation: 3a + 1=-a + 3?

(1) - 6

(2) 8

(3) - 1

(4) 5

None, the answer should be a=1/2

Step-by-step explanation:

Lets solve the system by ourselves.

Lets sum 'a' variable to both sides of equality sign.

We have

4a+1=3

Now lets subtract 1 to both sides of equality sign

4a=2

we obtain a=1/2.