Question

Substitute the isolated variable into the second equation. I need help with this, i don’t understand.

Answer 1

Explanation:

Substitute the value for y or x into the equation thats listed with it.

For the first one, substitute 3 in place of y.

3x + 6 y = 60 turns into

3x + 6 * 3 = 60

3x + 18 = 60

3x = 60-18

3x = 42

x = 42/3

x = 14

Apply the same to the other equations

10x + 4y = 70 turns into

10 * 5 + 4y = 70

Then solve for y