# How do you reduce -8 + b^2 by 5 + b^2?

May 4, 2018

By subtracting $- 13$

#### Explanation:

How do you reduce $20$ by $8$,

of course by $\textcolor{red}{\text{subtracting }} 12$, which means $20 - 8$ i.e. subtract latter number $8$ from former number $20$

Hence to reduce $- 8 + {b}^{2}$ by $5 + {b}^{2}$,

we should subtract latter number $5 + {b}^{2}$ from former number $- 8 + {b}^{2}$ i.e.

$- 8 + {b}^{2} - \left(5 + {b}^{2}\right)$

= $- 8 + {b}^{2} - 5 - {b}^{2}$

= $- 13$

i.e. by subtracting $- 13$