How do you solve y=4x-9 y=x-3

y=4x-9; y=x-3

Solve y=4x-9 for y:

Substitute (4x-9) for y in y=x-3:

y=x-3

4x-9=x-3

4x-9+-x=x-3+-x (Add - x to both sides)

3x-9=-3

3x-9+9=-3+9 (Add 9 to both sides)

3x=6

3x/3=6/3 (Divide both sides by 3)

x=2

Substitute (2) for x in y=4x-9:

y=4x-9

y = (4) (2) - 9

y=-1 (Simplify both sides of the equation)

x=2

y=-1

Y = 4x-9

y = x-3

By the substitution property ...

4x-9 = x-3

Add 9 to each side to get rid of the - 9.

4x = x+6

Subtract x from each side to get rid of the x on the right.

3x = 6

Divide by 3.

x = 2

Use x = 2 in an earlier equation to find y.

y = x-3

y = 2-3

y = - 1

As an ordered pair, the intersection of these lines is at (-1, 2).