(d-7)(d+7)=

Solution for (d-7)(d+7)= equation:

Simplifying
(d + -7)(d + 7) = 0

Reorder the terms:
(-7 + d)(d + 7) = 0

Reorder the terms:
(-7 + d)(7 + d) = 0

Multiply (-7 + d) * (7 + d)
(-7(7 + d) + d(7 + d)) = 0
((7 * -7 + d * -7) + d(7 + d)) = 0
((-49 + -7d) + d(7 + d)) = 0
(-49 + -7d + (7 * d + d * d)) = 0
(-49 + -7d + (7d + d2)) = 0

Combine like terms: -7d + 7d = 0
(-49 + 0 + d2) = 0
(-49 + d2) = 0

Solving
-49 + d2 = 0

Solving for variable 'd'.

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

Add '49' to each side of the equation.
-49 + 49 + d2 = 0 + 49

Combine like terms: -49 + 49 = 0
0 + d2 = 0 + 49
d2 = 0 + 49

Combine like terms: 0 + 49 = 49
d2 = 49

Simplifying
d2 = 49

Take the square root of each side:
d = {-7, 7}