Substitution to solve the linear system

y=4x+2. eq1
y=5x. eq2
4x=2-y
x=(2-y) /4
substitute in equation 2
y=5(2-y) /2
y=(10-5y)/2
4y=10-5y
9y=10
y=10/9
substitute in equation 2 or 1
substituting in equation 2
10/9=5x
x=10/45
x=10/45 y=10/9
you can verify it also.
HOPE IT HELPS!!