Question

8x-2y = 18
y = 4x - 9
Solve by substitution

Answer 1

x= 3 y= 3
8(3) -2(3)= 18
24 - 6 = 18
y(3) = 4(3) - 9
3 = 12- 9

Answer 2

• Infinitely many solutions

Explanation:

Given system:

• 8x - 2y = 18
• y = 4x - 9

Solve by substitution:

• 8x - 2(4x - 9) = 18
• 8x - 8x + 18 = 18
• 18 = 18

We got correct equation without variables.

It means the equation is correct for any value of variables, the lines are same and overlap.

So there are infinitely many solutions.