Question

Solve this equation for x in terms of y and z:

9x + 3y + 4z = 24
What is the value of x when y = 9 and z=-12?

Answer 1

3y = 3 * 9 = 27
4z = 4 * -12 = -48
: -48 + 27 = -21
: -21 + x = 24
: X = 45.
I hope that makes sense.

Answer 2

x = 5

Explanation:

9x + 3y + 4z = 24

9x + 3(9) + 4(-12) = 24

9x + 27 + (-48) = 24

9x + 27 - 48 = 24

9x - 21 = 24

9x = 24 + 21

9x = 45

x = 45 ÷ 9

x = 5