Pre-Algebra Examples

$(8 r^{2} - 7 r - 9) + (- r^{2} + r)$

Step 1

Remove parentheses.

$8 r^{2} - 7 r - 9 - r^{2} + r$

Step 2

Subtract $r^{2}$ from $8 r^{2}$ .

$7 r^{2} - 7 r - 9 + r$

Step 3

Add $- 7 r$ and $r$ .

$7 r^{2} - 6 r - 9$

$[\begin{array}{c} x^{2} & \frac{1}{2} \\ \sqrt{π} & \int x d x \end{array}]$