How do you multiply and simplify #\sqrt { 72} \cdot \sqrt { 18}#?

2 Answers
Apr 9, 2018

#36#

Explanation:

#"using the "color(blue)"laws of radicals"#

#•color(white)(x)sqrtaxxsqrtbhArrsqrt(ab)#

#•color(white)(x)sqrtaxxsqrta=a#

#rArrsqrt72=sqrt(36xx2)=sqrt36xxsqrt2=6sqrt2#

#rArrsqrt18=sqrt(9xx2)=sqrt9xxsqrt2=3sqrt2#

#rArrsqrt72xxsqrt18#

#=6sqrt2xx3sqrt2#

#=(6xx3)xx(sqrt2xxsqrt2)#

#=18xx2=36#

Apr 9, 2018

In a common square root. You will get 36 at the end.

Explanation:

#sqrt(72times18)#

#=sqrt(1296)#

#=sqrt(36times36)#

#=36#

Your answer is 36.