(10+z)*(10-z)=36

Solution for (10+z)*(10-z)=36 equation:

Simplifying
(10 + z)(10 + -1z) = 36

Multiply (10 + z) * (10 + -1z)
(10(10 + -1z) + z(10 + -1z)) = 36
((10 * 10 + -1z * 10) + z(10 + -1z)) = 36
((100 + -10z) + z(10 + -1z)) = 36
(100 + -10z + (10 * z + -1z * z)) = 36
(100 + -10z + (10z + -1z2)) = 36

Combine like terms: -10z + 10z = 0
(100 + 0 + -1z2) = 36
(100 + -1z2) = 36

Solving
100 + -1z2 = 36

Solving for variable 'z'.

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

Add '-100' to each side of the equation.
100 + -100 + -1z2 = 36 + -100

Combine like terms: 100 + -100 = 0
0 + -1z2 = 36 + -100
-1z2 = 36 + -100

Combine like terms: 36 + -100 = -64
-1z2 = -64

Divide each side by '-1'.
z2 = 64

Simplifying
z2 = 64

Take the square root of each side:
z = {-8, 8}