Question

How do you multiply `-4\sqrt { 20k } \cdot \sqrt { 5k ^ { 3} }`?

Answer 1

`-40k^2`
`color(white)("XXX")`see below for method of solution

Explanation:

`color(magenta)(-4)sqrt(color(red)(20k))sqrt(color(blue)(5k^3))`

`color(white)("XXX")=color(magenta)(-4) * sqrt(color(red)(2 * 2 * 5 * k) * color(blue)(5 * k^3))`

`color(white)("XXX")=color(magenta)(-4) * sqrt(2^2 * 5 ^2 * (k^2)^2)`

`color(white)("XXX")=color(magenta)(-4) * (2 * 5 * k^2)`

`color(white)("XXX")= -40k^2`