How do you simplify #5sqrt(-75) - 9sqrt(-300)#?

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Answer 1 · 2016-01-27T09:59:05

You use the rule #sqrt(a*b)=sqrt(a)*sqrt(b)#

#-65sqrt(3)i#

Note DON'T fall into the trap of simplifying the minus signs of the roots with the outer signs.

#5sqrt(-75)-9sqrt(-300)#

#5sqrt(-3*2)-9sqrt(-3*100)#

#5sqrt(-3)*sqrt(25)-9sqrt(-3)*sqrt(100)#

#5*5*sqrt(-3)-9sqrt(-3)*10#

#25*sqrt(-3)-90sqrt(-3)#

#i25*sqrt(3)-i90sqrt(3)#

#isqrt(3)*(25-90)#

#-65sqrt(3)i#