System of Equations-Elimination

1. 2x + 7y=1
x + 5y=2


2. -5x + 3y=6
x-y=4


3. 4x - 3y=12
x + 2y=14



If you can solve these using system of equations it would be a HUGE help! Thanks!

Standard form: 2x+7y=1; x+5y=2;
substitute/eliminate x = -7/2y+1/2
substitute/eliminate y = +1
Solution: x = -3; y = 1;
(x, y) = (-3, 1)

Standard form: -5x+3y=6; x-y=4;
substitute/eliminate x = +3/5y-6/5
substitute/eliminate y = -13
Solution: x = -9; y = -13;
(x, y) = (-9, -13)

Standard form: 4x-3y=12; x+2y=14;
substitute/eliminate x = +3/4y+3
substitute/eliminate y = +4
Solution: x = 6; y = 4;
(x, y) = (6, 4)