3r^2-8r+90=0

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Solution for 3r^2-8r+90=0 equation:


Simplifying
3r2 + -8r + 90 = 0

Reorder the terms:
90 + -8r + 3r2 = 0

Solving
90 + -8r + 3r2 = 0

Solving for variable 'r'.

Begin completing the square.  Divide all terms by
3 the coefficient of the squared term: 

Divide each side by '3'.
30 + -2.666666667r + r2 = 0

Move the constant term to the right:

Add '-30' to each side of the equation.
30 + -2.666666667r + -30 + r2 = 0 + -30

Reorder the terms:
30 + -30 + -2.666666667r + r2 = 0 + -30

Combine like terms: 30 + -30 = 0
0 + -2.666666667r + r2 = 0 + -30
-2.666666667r + r2 = 0 + -30

Combine like terms: 0 + -30 = -30
-2.666666667r + r2 = -30

The r term is -2.666666667r.  Take half its coefficient (-1.333333334).
Square it (1.777777780) and add it to both sides.

Add '1.777777780' to each side of the equation.
-2.666666667r + 1.777777780 + r2 = -30 + 1.777777780

Reorder the terms:
1.777777780 + -2.666666667r + r2 = -30 + 1.777777780

Combine like terms: -30 + 1.777777780 = -28.22222222
1.777777780 + -2.666666667r + r2 = -28.22222222

Factor a perfect square on the left side:
(r + -1.333333334)(r + -1.333333334) = -28.22222222

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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