# How do you multiply (7a^4+2a^2)(a-5)?

May 27, 2017

color(blue)(7a^5-35a^4+2a^3-10a^2

#### Explanation:

$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$7 {a}^{4} + 2 {a}^{2}$
$\textcolor{w h i t e}{a a a a a a a a a a a}$$\times \underline{a - 5}$
$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$7 {a}^{5} + 2 {a}^{3}$
$\textcolor{w h i t e}{a a a a a a a a a a a a a a a a a a a a a a}$$- 35 {a}^{4} - 10 {a}^{2}$
$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$\overline{7 {a}^{5} + 2 {a}^{3} - 35 {a}^{4} - 10 {a}^{2}}$

arrange the terms in decreasing power:

color(blue)(7a^5-35a^4+2a^3-10a^2