d^2-8d+7=0

Solution for d^2-8d+7=0 equation:

Simplifying
d2 + -8d + 7 = 0

Reorder the terms:
7 + -8d + d2 = 0

Solving
7 + -8d + d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(1 + -1d)(7 + -1d) = 0

Subproblem 1
Set the factor '(1 + -1d)' equal to zero and attempt to solve:

Simplifying
1 + -1d = 0

Solving
1 + -1d = 0

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

Add '-1' to each side of the equation.
1 + -1 + -1d = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -1d = 0 + -1
-1d = 0 + -1

Combine like terms: 0 + -1 = -1
-1d = -1

Divide each side by '-1'.
d = 1

Simplifying
d = 1
Subproblem 2
Set the factor '(7 + -1d)' equal to zero and attempt to solve:

Simplifying
7 + -1d = 0

Solving
7 + -1d = 0

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

Add '-7' to each side of the equation.
7 + -7 + -1d = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -1d = 0 + -7
-1d = 0 + -7

Combine like terms: 0 + -7 = -7
-1d = -7

Divide each side by '-1'.
d = 7

Simplifying
d = 7
Solution
d = {1, 7}