Question

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

Answer 1

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

Answer 2

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).