By using method of substitution we need to solve one equation for a variable and plug in that equation in the second equation.
Let's solve the first equation for y of the given system of equation.
So, -4x+y=3
4x-4x+y=4x+3 Add 4x to each sides of the equation.
y= 4x+3.
Next step is to plug in 4x+3 for y in the second equation. Hence, after substituting we will get:
2x-(4x+3)=12.
Hence the correct choice is A) 2x - (4x + 3) = 12.