x^2 = 15 help?

Question

solve x^2 = 15
solve x^2 + 9 = 18
I cannot figure these out

Answer 1

Simplifying
x^2 = 15

Solving
x^2 = 15

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Simplifying
x^2 = 15

Take the square root of each side:
x = {-3.872983346, 3.872983346}




Simplifying
x^2 + 9 = 18

Reorder the terms:
9 + x^2 = 18

Solving
9 + x^2 = 18

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-9' to each side of the equation.
9 + -9 + x^2 = 18 + -9

Combine like terms: 9 + -9 = 0
0 + x^2 = 18 + -9
x^2 = 18 + -9

Combine like terms: 18 + -9 = 9
x^2 = 9

Simplifying
x^2 = 9

Take the square root of each side:
x = {-3, 3}

Answer 2

x^2=15. x= square root of 15.

x^2 +9=18, x^2= 18-9=9.
x= +3, x= - 3.

Answer 3

x² + 9 = 18 subtract 9 from both sides
x² = 9
x = ±3

Answer 4

x^2=15
x=sqrt of 15=sqrt of 3 * sqrt of 5 or sqrt of3i * sqrt of 5i

x^2+9=18
x^2+9-9=18-9
x^2=9
x=3or -3