Question

solve the system of equations below by using substitution
x + y = 30
y = 9x.
x + __ = 30
__ = 30
x = __
y = 9 x __
y = __
solution is (__, __)

Answers: 10, 30, x, 18, 12, y, 3, 9x, 10x and 2x
27 IS NOT PART OF THE ANSWERS.

Answer 1

Substitute y = 9x into x + y = 30:

x + 9x = 30
10x = 30
x = 3
y = 9 × 3
y = 27

So the solution is (3, 27).

If you must fill the blanks from the provided options, use:
- x + __ = 30 → x + 9x = 30 (choose 9x)
- __ = 30 → 10x = 30 (choose 10x)
- x = __ → x = 3 (choose 3)
- y = 9 x __ → y = 9 x 3 (choose 3)
- y = __ → y = 27 (note: 27 is not in the given answer list)

Final solution: (3, 27).