+129840 7x=3y+15 rearrange as 7x - 3y = 15
3x-2y=15
Multiply the first equation by 2 and the second by -3
14x - 6y = 30
-9x + 6y = -45 add these giving
5x = - 15 divide both sides by 5
x = -3
And using
7x = 3y+15 → 7(-3) = 3y + 15 → - 21 = 3y + 15 → -21 - 15 = 3y → - 36 = 3y → -12 = y
