4a^2+8a-21=0

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Solution for 4a^2+8a-21=0 equation:


Simplifying
4a2 + 8a + -21 = 0

Reorder the terms:
-21 + 8a + 4a2 = 0

Solving
-21 + 8a + 4a2 = 0

Solving for variable 'a'.

Factor a trinomial.
(-7 + -2a)(3 + -2a) = 0

Subproblem 1

Set the factor '(-7 + -2a)' equal to zero and attempt to solve: Simplifying -7 + -2a = 0 Solving -7 + -2a = 0 Move all terms containing a to the left, all other terms to the right. Add '7' to each side of the equation. -7 + 7 + -2a = 0 + 7 Combine like terms: -7 + 7 = 0 0 + -2a = 0 + 7 -2a = 0 + 7 Combine like terms: 0 + 7 = 7 -2a = 7 Divide each side by '-2'. a = -3.5 Simplifying a = -3.5

Subproblem 2

Set the factor '(3 + -2a)' equal to zero and attempt to solve: Simplifying 3 + -2a = 0 Solving 3 + -2a = 0 Move all terms containing a to the left, all other terms to the right. Add '-3' to each side of the equation. 3 + -3 + -2a = 0 + -3 Combine like terms: 3 + -3 = 0 0 + -2a = 0 + -3 -2a = 0 + -3 Combine like terms: 0 + -3 = -3 -2a = -3 Divide each side by '-2'. a = 1.5 Simplifying a = 1.5

Solution

a = {-3.5, 1.5}

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