Question

solve by substitution method:8x+4y=4 _2x=y+4

Answer 1

yes

Answer 2

You are given two equations. Rearrange one of them using algebra to get in the form:
y = f(x)
or
x = f(y)
once you have that, substitute your new y into the second equation.
[NOTE: your second equation should only have 1 variable, either all x's or all y's. whichever you chose to substitute for].
Combine like terms and solve for x (or y). Then, plug in that new value into the first equation and solve for y (or x).