How do you simplify #14sqrt20 - 3sqrt125#?
2 Answers
Jul 2, 2016
Explanation:
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Jul 2, 2016
Explanation:
Note that if
#sqrt(ab) = sqrt(a)sqrt(b)#
In particular:
#sqrt(a^2b) = sqrt(a^2)sqrt(b) = asqrt(b)#
So we can move square factors outside the square root like this:
#14sqrt(20)-3sqrt(125)#
#=14sqrt(2^2*5)-3sqrt(5^2*5)#
#=14sqrt(2^2)sqrt(5)-3sqrt(5^2)sqrt(5)#
#=(14*2*sqrt(5))-(3*5*sqrt(5))#
#=28sqrt(5)-15sqrt(5)#
#=(28-15)sqrt(5)#
#=13sqrt(5)#
