Question 134920
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*sqrt(2)}}}; 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(3)}}}
:
5x^2 - 12 = 5
5x^2 = 5 + 12
5x^2 = 17
x^2 = 17/5
x = +/-{{{sqrt(17/5)}}}