Solve =2pi*r(1/pi*r^2)+2pi*r^2

$$= 2 \pi \cdot r ( \frac { 1 } { \pi \cdot r ^ { 2 } } ) + 2 \pi \cdot r ^ { 2 }$$

Evaluate

$$\frac{2\left(\pi r^{3}+1\right)}{r}$$

Short Solution Steps

Express 2\times \frac{1}{\pi r^{2}} as a single fraction.

$$\frac{2}{\pi r^{2}}\pi r+2\pi r^{2}$$

Express \frac{2}{\pi r^{2}}\pi as a single fraction.

$$\frac{2\pi }{\pi r^{2}}r+2\pi r^{2}$$

Cancel out \pi in both numerator and denominator.

$$\frac{2}{r^{2}}r+2\pi r^{2}$$

Express \frac{2}{r^{2}}r as a single fraction.

$$\frac{2r}{r^{2}}+2\pi r^{2}$$

Cancel out r in both numerator and denominator.

$$\frac{2}{r}+2\pi r^{2}$$

To add or subtract expressions, expand them to make their denominators the same. Multiply 2\pi r^{2} times \frac{r}{r}.

$$\frac{2}{r}+\frac{2\pi r^{2}r}{r}$$

Since \frac{2}{r} and \frac{2\pi r^{2}r}{r} have the same denominator, add them by adding their numerators.

$$\frac{2+2\pi r^{2}r}{r}$$

Do the multiplications in 2+2\pi r^{2}r.

$$\frac{2+2\pi r^{3}}{r}$$

Factor

$$\frac{2\left(\pi r^{3}+1\right)}{r}$$