Question

- If 2x2 + 8y = 121.5 and x2 - 8y = 121.5, then x =
9
6.36
16
7

Answer 1

Explanation:

2x² + 8y = 121.5

x² - 8y = 121.5

Add the equations together to eliminate the y terms.

3x² = 243

x² = 81

x = 9