4x-4y=0

Y=2x+6

Solve by substitution

Answer: x = - 6, and y = - 6 (-6, - 6)

Step-by-step explanation: What we have here is a pair of simultaneous equations. Since we have been instructed to solve by substitution, we shall begin with the one which has one of the variables as having a coefficient of 1. We shall start with equation 2 which is,

y = 2x + 6

Having taken note of this, we can now go on to the other equation and substitute for the value of y.

Hence, from equation 1,

4x - 4y = 0 (substitute for the value of y)

4x - 4 (2x + 6) = 0

4x - 8x - 24 = 0

-4x - 24 = 0

Add 24 to both sides of the equation

-4x = 24

Divide both sides of the equation by - 4

x = - 6

Having calculated the value of x, we can now go on to substitute for the value of x in equation 2.

Therefore,

y = 2x + 6

y = 2 (-6) + 6

y = - 12 + 6

y = - 6.

So, x = - 6 and y = - 6