21x^2+13x-8=0

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Solution for 21x^2+13x-8=0 equation:


Simplifying
21x2 + 13x + -8 = 0

Reorder the terms:
-8 + 13x + 21x2 = 0

Solving
-8 + 13x + 21x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -1x)(8 + -21x) = 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 '(8 + -21x)' equal to zero and attempt to solve: Simplifying 8 + -21x = 0 Solving 8 + -21x = 0 Move all terms containing x to the left, all other terms to the right. Add '-8' to each side of the equation. 8 + -8 + -21x = 0 + -8 Combine like terms: 8 + -8 = 0 0 + -21x = 0 + -8 -21x = 0 + -8 Combine like terms: 0 + -8 = -8 -21x = -8 Divide each side by '-21'. x = 0.380952381 Simplifying x = 0.380952381

Solution

x = {-1, 0.380952381}

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