Question

How do you simplify `(8r ^ { 2} + 2r + 8) ( 7r + 1)`?

Answer 1

`=56r^3 +22r^2 +58r +8`

Explanation:

Get rid of the brackets by multiplying using the distributive law:

`color(red)((8r^2+2r+8))(7r+1)`

`= color(red)(8r^2)(7r+1) + color(red)(2r)(7r+1) +color(red)(8)(7r+1)`

`=56r^3+8r^2 +14r^2+2r +56r +8`

`=56r^3 +22r^2 +58r +8`

Answer 2

`color(green)(56r^3+22r^2+58r+8`

Explanation:

`(8r^2+2r+8)(7r+1)`

`color(white)(aaaaaaaaaaaaa)` `8r^2+2r+8`
`color(white)(aaaaaaaaaa)` `xx underline(7r+1)`
`color(white)(aaaaaaaaaaaaa)` `56r^3+14r^2+56r`
`color(white)(aaaaaaaaaaaaaaaaaaaa)` `8r^2+2r+8`
`color(white)(aaaaaaaaaaaaa)` `overline(56r^3+22r^2+58r+8)`

`color(white)(aaaaaaaaaaaaa)` `color(green)(56r^3+22r^2+58r+8`