Question

What is -4 square root of 90 + 2 square root of 160?

Answer 1

`-4sqrt(10)`

Explanation:

`sqrt(90)`
`color(white)("XX")=sqrt(3^2xx10) = 3sqrt(10)`

`sqrt(160)`
`color(white)("XX")=sqrt(4^2xx10) = 4sqrt(10)`

Therefore
`color(red)(-4sqrt(90)) + color(blue)(2sqrt(160))`

`color(white)("XX")=color(red)((-4)(3sqrt(10))) +color(blue)((2)(4sqrt(10)))`

`color(white)("XX")=color(red)(-12sqrt(10))+ color(blue)(8sqrt(10))`

`color(white)("XX")=-4sqrt(10)`