18r^2+21r=9

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Solution for 18r^2+21r=9 equation:


Simplifying
18r2 + 21r = 9

Reorder the terms:
21r + 18r2 = 9

Solving
21r + 18r2 = 9

Solving for variable 'r'.

Reorder the terms:
-9 + 21r + 18r2 = 9 + -9

Combine like terms: 9 + -9 = 0
-9 + 21r + 18r2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(-3 + 7r + 6r2) = 0

Factor a trinomial.
3((-3 + -2r)(1 + -3r)) = 0

Ignore the factor 3.

Subproblem 1

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

Subproblem 2

Set the factor '(1 + -3r)' equal to zero and attempt to solve: Simplifying 1 + -3r = 0 Solving 1 + -3r = 0 Move all terms containing r to the left, all other terms to the right. Add '-1' to each side of the equation. 1 + -1 + -3r = 0 + -1 Combine like terms: 1 + -1 = 0 0 + -3r = 0 + -1 -3r = 0 + -1 Combine like terms: 0 + -1 = -1 -3r = -1 Divide each side by '-3'. r = 0.3333333333 Simplifying r = 0.3333333333

Solution

r = {-1.5, 0.3333333333}

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