Answer:
x = 6; y = 1 1/2
Explanation:
Since the first equation is already solved for y, use the substitution method.
y = -1/2 x + 4 1/2
3x - 4y = 12
3x - 4(-1/2 x + 9/2) = 12
3x + 2x - 18 = 12
5x = 30
x = 6
Now substitute x = 6 in the first original equation to find y.
y = -1/2 x + 9/2
y = -1/2(6) + 9/2
y = -3 + 9/2
y = -6/2 + 9/2
y = 3/2 = 1 1/2
Answer: x = 6; y = 1 1/2