9=10-z^2

Solution for 9=10-z^2 equation:

Simplifying
9 = 10 + -1z2

Solving
9 = 10 + -1z2

Solving for variable 'z'.

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

Add 'z2' to each side of the equation.
9 + z2 = 10 + -1z2 + z2

Combine like terms: -1z2 + z2 = 0
9 + z2 = 10 + 0
9 + z2 = 10

Add '-9' to each side of the equation.
9 + -9 + z2 = 10 + -9

Combine like terms: 9 + -9 = 0
0 + z2 = 10 + -9
z2 = 10 + -9

Combine like terms: 10 + -9 = 1
z2 = 1

Simplifying
z2 = 1

Take the square root of each side:
z = {-1, 1}