Question

Y= 4x - 9

y= x - 3

can someone pls help me solve this system of equations (using substitution)

Answer 1

(x, y) = (2, -1)

Explanation:

You want to solve this system using substitution.

• y = 4x -9
• y = x -3

Substitution

It works best to substitute for a variable that you already have an expression for. Here, you have two expressions for y. Substituting both for y, you get ...

y = y

4x -9 = x -3

3x = 6 . . . . . . . . add 9-x to both sides

x = 2 . . . . . . . . divide by 3

y = 2 -3 = -1 . . . . substitute for x in the second equation

The solution is (x, y) = (2, -1).