SOLUTION: 3x^2+7=31 7n^2-6=15 5x^2-12=5 what does x =

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Question 134920: 3x^2+7=31
7n^2-6=15
5x^2-12=5
what does x =

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Solve these using basic algebra operations
:
3x^2 + 7 = 31
3x^2 = 31 - 7; subtract 7 from both sides
3x^2 = 24
x^2 = 24/3; divide both sides by 3
x^2 = 8
x = +/-Sqrt(8); find the square root of both sides
x = +/-Sqrt(4*2); factor out 4, a perfect square
x = +/-2%2Asqrt%282%29; extract the square root of 4
:
7n^2 - 6 = 15
7n^2 = 15 + 6
7n^2 = 21
n^2 = 21/7
n^2 = 3
n = +/-sqrt%283%29
:
5x^2 - 12 = 5
5x^2 = 5 + 12
5x^2 = 17
x^2 = 17/5
x = +/-sqrt%2817%2F5%29