4x^2-21x-25=0

Solution for 4x^2-21x-25=0 equation:

Simplifying
4x2 + -21x + -25 = 0

Reorder the terms:
-25 + -21x + 4x2 = 0

Solving
-25 + -21x + 4x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -1x)(25 + -4x) = 0

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

Simplifying
-1 + -1x = 0

Solving
-1 + -1x = 0

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

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

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

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

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

Simplifying
x = -1
Subproblem 2
Set the factor '(25 + -4x)' equal to zero and attempt to solve:

Simplifying
25 + -4x = 0

Solving
25 + -4x = 0

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

Add '-25' to each side of the equation.
25 + -25 + -4x = 0 + -25

Combine like terms: 25 + -25 = 0
0 + -4x = 0 + -25
-4x = 0 + -25

Combine like terms: 0 + -25 = -25
-4x = -25

Divide each side by '-4'.
x = 6.25

Simplifying
x = 6.25
Solution
x = {-1, 6.25}