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Simplifying
1306.7424 = 4 * 3.14r2
Multiply 4 * 3.14
1306.7424 = 12.56r2
Solving
1306.7424 = 12.56r2
Solving for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Add '-12.56r2' to each side of the equation.
1306.7424 + -12.56r2 = 12.56r2 + -12.56r2
Combine like terms: 12.56r2 + -12.56r2 = 0.00
1306.7424 + -12.56r2 = 0.00
Add '-1306.7424' to each side of the equation.
1306.7424 + -1306.7424 + -12.56r2 = 0.00 + -1306.7424
Combine like terms: 1306.7424 + -1306.7424 = 0.0000
0.0000 + -12.56r2 = 0.00 + -1306.7424
-12.56r2 = 0.00 + -1306.7424
Combine like terms: 0.00 + -1306.7424 = -1306.7424
-12.56r2 = -1306.7424
Divide each side by '-12.56'.
r2 = 104.04
Simplifying
r2 = 104.04
Take the square root of each side:
r = {-10.2, 10.2}
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