Solve for r
r = \frac{\sqrt{10990}}{70} \approx 1.497617155
r = -\frac{\sqrt{10990}}{70} \approx -1.497617155
Share
Copied to clipboard
3150r^{2}=7065
Multiply 105 and 30 to get 3150.
r^{2}=\frac{7065}{3150}
Divide both sides by 3150.
r^{2}=\frac{157}{70}
Reduce the fraction \frac{7065}{3150} to lowest terms by extracting and canceling out 45.
r=\frac{\sqrt{10990}}{70} r=-\frac{\sqrt{10990}}{70}
Take the square root of both sides of the equation.
3150r^{2}=7065
Multiply 105 and 30 to get 3150.
3150r^{2}-7065=0
Subtract 7065 from both sides.
r=\frac{0±\sqrt{0^{2}-4\times 3150\left(-7065\right)}}{2\times 3150}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3150 for a, 0 for b, and -7065 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
r=\frac{0±\sqrt{-4\times 3150\left(-7065\right)}}{2\times 3150}
Square 0.
r=\frac{0±\sqrt{-12600\left(-7065\right)}}{2\times 3150}
Multiply -4 times 3150.
r=\frac{0±\sqrt{89019000}}{2\times 3150}
Multiply -12600 times -7065.
r=\frac{0±90\sqrt{10990}}{2\times 3150}
Take the square root of 89019000.
r=\frac{0±90\sqrt{10990}}{6300}
Multiply 2 times 3150.
r=\frac{\sqrt{10990}}{70}
Now solve the equation r=\frac{0±90\sqrt{10990}}{6300} when ± is plus.
r=-\frac{\sqrt{10990}}{70}
Now solve the equation r=\frac{0±90\sqrt{10990}}{6300} when ± is minus.
r=\frac{\sqrt{10990}}{70} r=-\frac{\sqrt{10990}}{70}
The equation is now solved.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}