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)
y=-1
x=2
