Hi Andres,

The "triple" equation x = y - 2 = (y + 5)/2 is compact way of writing three separate equations:

1) x = y - 2
2) y - 2 = (y + 5)/2
3) x = (y + 5)/2

We will use only equations 1 and 2 to find the value of x. Multiplying both sides of Equation 2 by 2 yields

2(y - 2) = y + 5

Distributing the 2 on the left-hand side of this equation yields

2y - 4 = y + 5

Subtracting y and adding 4 to both sides yields

y = 9

Now, replacing y with 9 in Equation 1 yields

x = y - 2 = 9 - 2 = 7

Hence, the answer is E.

Nova Press