-7x + 9y = -29
8x + 5y = -28
multipy the top equation by 8, the second equation by 7
-56x+72y=-29*8
56x+35y=-28*7
add the two equaitons
105y= sum above right side, then solve for y.
8x + 5y = -28
-56x+72y=-29*8
56x+35y=-28*7
add the two equaitons
105y= sum above right side, then solve for y.