Question

How to solve y=4x-9
y=x-3

Answer 1

`\begin{cases} y=4x-9 \\ y=x-3 \end{cases} \\ \\ 4x-9=x-3 \\ \\ 3x=6 \\ \\ x=2 \\ \\ y=2-3 \\ \\ y=-1`

Answer 2

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