How do you simplify (2sqrt5 - 4sqrt6) (3sqrt3 + 8sqrt2)?

1 Answer
Mar 5, 2018

(2sqrt5-4sqrt6)(3sqrt3+8sqrt2)=6sqrt15+16sqrt10-36sqrt2-64sqrt3)

Explanation:

(2sqrt5-4sqrt6)(3sqrt3+8sqrt2)

Expand using the FOIL method.

![https://formulas.tutorvista.com/math/http://foil-formula.html](https://useruploads.socratic.org/acBP91UfQhOkevjTpxjU_foil-method.PNG)

(2sqrt5-4sqrt6)(3sqrt3+8sqrt2)=

color(blue)((2sqrt5*3sqrt3))+color(teal)((2sqrt5*8sqrt2))+color(red)((-4sqrt6*3sqrt3))+color(green)((-4sqrt6*8sqrt2)

Multiply integers and square roots.

color(blue)((2*3*sqrt5sqrt3))+color(teal)((2*8*sqrt5sqrt2))+color(red)((-4*3*sqrt6sqrt3))+color(green)((-4*8*sqrt6sqrt2))

Simplify.

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-12sqrt18))+color(green)((-32sqrt12))

The first two sets of parentheses are cannot be simplified further. The second two sets of parentheses need further simplification.

Prime factorize color(red)((-12sqrt18)).

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-12sqrt(2*3*3))+color(green)((-32sqrt12)

Simplify.

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-12*3sqrt2))+color(green)((-32sqrt12))

Simplify.

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-36sqrt2))+color(green)((-32sqrt12))

Prime factorize color(green)((-32sqrt12)).

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-36sqrt2))+color(green)((-32sqrt(2*2*3)))

Simplify.

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-36sqrt2))+color(green)((-32*2sqrt3))

Simplify.

color(blue)((6sqrt15))+color(teal)((16sqrt10))+color(red)((-36sqrt2))+color(green)((-64sqrt3))

Simplify.

6sqrt15+16sqrt10-36sqrt2-64sqrt3