In order to solve using substitution, we'll need to first isolate one variable in one equation. I will be using 7x - 2y = 3 and solving for y to begin.
7x - 2y = 3
-2y = -7x + 3
2y = 7x - 3
y = 3.5x - 1.5
Next, we'll plug in our value of y (found above) into the equation 3x + 4y = 11 and solve for x.
3x + 4(3.5x - 1.5) = 11
3x + 14x - 6 = 11
17x = 17
x = 1
Finally, we'll plug our value of x in to the first equation (7x - 2y = 3) and solve for y.
7(1) - 2y = 3
7 - 2y = 3
-2y = -4
y = 2
The solution to these equations is (1, 2).
Hope this helps! :)