solve the linear system using substitution .

Question

4x-y=5

4x-4y=-4

Answer 1

4x - y = 5

4x = 5 + y

4x - 5 = y         Substitute into the second equation.

 

4x - 4(4x - 5) =-4

4x -16x +20 = -4

-12x + 20 = -4

-12x = - 24

x = 2                Substitute 2 into either of the first two equiations.

 

4(2) - y = 5

8 - y = 5

-y = -3

y = 3

 

{(2, 3)}