How do you solve #(r+7)^(3/2) = 729#?

Question

719 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-01-25T07:15:01

Step by step working is shown below.

#(r+7)^(3/2) = 729#

To solve we can square both sides, this would remove the radical.

#(r+7)^3 = 729^2#

#(r+7)^3 = (9^3)^2#

#(r+7)^3 = (9^2)^3#

Now take cube root on both the sides.

#root(3)((r+7))^3 = root(3)((9^2))^3#

#r+7 = 9^2#

#r+7 = 81#

#r=81-7#

#r=74#