7x - 3y = 4 2x - 4y = 1 The solution to the system of equations is

7x-3y=4 ..............(1)
2x-4y=1...............(2)

4(1)-3(2)   [-4 is the coefficient of y in (2), -3 is the coefficient of y in (1) ]
28x-12y = 16...........(1a)
6x-12y = 3...............(2a)
Subtract
22x = 13
solve
x=13/22 ....................(3)

Substitute (3) in (1)
7(13/22)-3(y)=4
solve for y
91/22-3y=4
3y=(91-88)/22=3/22
y=1/22

Answer: the solution is (13/22, 1/22)