Question

How do I solve: x^2+3=84.

Answer 1

x=9, x=-9

Explanation:

subtract 3 from both sides

x^2=81

then squareroot both sides (remember that there is a positive and negative solution!)

x=9, x=-9

Answer 2

x = -9

x = 9

Explanation:

`x^(2) + 3 = 84`

Subtract 84 from both sides.

`x^(2) + 3 - 84 = 0`

Subtract 84 from 3 to get −81.

`x^(2) - 81 = 0`

Consider
`x^(2)` - 81. Rewrite
`x^(2) - 81` as
`x^(2) - 9^(2)`. The difference of squares can be factored in using the rule:
`a^(2) - b^(2) = ( a- b) ( a+ b)`.

`(x - 9) (x + 9) = 0`

To find equation solutions, solve
`x - 9 = 0` and
`x + 9 = 0`

x = 9

x = -9

Hope it helps and have a great day! =D

~sunshine~