MATH SOLVE

4 months ago

Q:
# If 2x2 + 8y = 121.5 and x2 - 8y = 121.5, then x =

Accepted Solution

A:

2x² +8y = 121.5

8y = 121.5 - 2x²

and,

x²-8y = 121.5

-8y = 121.5 -x²

8y = x²-121.5

Now, equate the two 8y's

121.5-2x² = x² -121.5

-3x² = -121.5-121.5

-3x² = -243

3x² = 243

x² = 81

x = ±9

8y = 121.5 - 2x²

and,

x²-8y = 121.5

-8y = 121.5 -x²

8y = x²-121.5

Now, equate the two 8y's

121.5-2x² = x² -121.5

-3x² = -121.5-121.5

-3x² = -243

3x² = 243

x² = 81

x = ±9