Multiply:

(5√3 - 15√5)(2√3 + 6√5)

(5√3 - 15√5)(2√3 + 6√5)

= 5√3(2√3) + 5√3(6√5) - 15√5(2√3) - 15√5(6√5) {used foil method}

= 10√9 + 30√15 - 30√15 - 90√25 {multiplied through}

= 10(3) - 90(5) {evaluated square roots of 9 and 25, and combined like terms}

= 30 - 450 {multiplied}

=

**- 420**{combined like terms}

*© Algebra House*