9r^2-30r+21=-4

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Solution for 9r^2-30r+21=-4 equation:


Simplifying
9r2 + -30r + 21 = -4

Reorder the terms:
21 + -30r + 9r2 = -4

Solving
21 + -30r + 9r2 = -4

Solving for variable 'r'.

Reorder the terms:
21 + 4 + -30r + 9r2 = -4 + 4

Combine like terms: 21 + 4 = 25
25 + -30r + 9r2 = -4 + 4

Combine like terms: -4 + 4 = 0
25 + -30r + 9r2 = 0

Factor a trinomial.
(5 + -3r)(5 + -3r) = 0

Subproblem 1

Set the factor '(5 + -3r)' equal to zero and attempt to solve: Simplifying 5 + -3r = 0 Solving 5 + -3r = 0 Move all terms containing r to the left, all other terms to the right. Add '-5' to each side of the equation. 5 + -5 + -3r = 0 + -5 Combine like terms: 5 + -5 = 0 0 + -3r = 0 + -5 -3r = 0 + -5 Combine like terms: 0 + -5 = -5 -3r = -5 Divide each side by '-3'. r = 1.666666667 Simplifying r = 1.666666667

Subproblem 2

Set the factor '(5 + -3r)' equal to zero and attempt to solve: Simplifying 5 + -3r = 0 Solving 5 + -3r = 0 Move all terms containing r to the left, all other terms to the right. Add '-5' to each side of the equation. 5 + -5 + -3r = 0 + -5 Combine like terms: 5 + -5 = 0 0 + -3r = 0 + -5 -3r = 0 + -5 Combine like terms: 0 + -5 = -5 -3r = -5 Divide each side by '-3'. r = 1.666666667 Simplifying r = 1.666666667

Solution

r = {1.666666667, 1.666666667}

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