Answer:
a = 1
Step-by-step explanation:
Adding 3 as x into the equation will give you 2(3) + y = 7. 3 x 2 = 6, so now the equation is 6 + y = 7.
Now subtract 6 from both sides of the equation to get y by itself, so you'll have y = 1.
CHECK:
2(3) + 1 = 7
6 + 1 = 7
7 = 7 ⇆
