Question

2x - 4y = 12 3x - 5y = 20

Answer 1

You multiply the first equation by 3 and the second one by 2:
3*(2x - 4y = 12) = 6x - 12y = 36
2*(3x - 5y =20) = 6x - 10y = 40
Then use elimination:
6x - 12y = 36
- (6x - 10y = 40)
= -2y = -4
Solve:
y = 2
Then, plug 2 into the first equation and solve:
2x - 4(2) = 12
2x - 8 = 12
2x = 20
x = 10
There is the answer, x = 10 and y = 2.