x^2+3x^2-25x+21=0

Solution for x^2+3x^2-25x+21=0 equation:

Simplifying
x2 + 3x2 + -25x + 21 = 0

Reorder the terms:
21 + -25x + x2 + 3x2 = 0

Combine like terms: x2 + 3x2 = 4x2
21 + -25x + 4x2 = 0

Solving
21 + -25x + 4x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(1 + -1x)(21 + -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 '(21 + -4x)' equal to zero and attempt to solve:

Simplifying
21 + -4x = 0

Solving
21 + -4x = 0

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

Add '-21' to each side of the equation.
21 + -21 + -4x = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -4x = 0 + -21
-4x = 0 + -21

Combine like terms: 0 + -21 = -21
-4x = -21

Divide each side by '-4'.
x = 5.25

Simplifying
x = 5.25
Solution
x = {1, 5.25}