I am 179% sure that your second equation is written incorrectly in this post.
I am 129% sure that the correct writing is THIS y = (1/2)x + 3, y = (-1/4)x-3
Left sides of these equations are identical --- hence, their right sides are equal
= .
Multiply both sides by 4 to rid of the denominators. You will get
2x + 12 = -x - 12
Collect the terms with x in the left side; combine the constant terms on the right.
2x + x = - 12 - 12
Combine like terms
3x = - 24
Hence, x = = -8.
Then y = = -4 + 3 = -1.
ANSWER. x= -8; y= -1.