need help mathhhhhhhhh?

Question

7cube root 243-cube root1125 +5 cube root 72
collecting like terms

Answer 1

if i got you right then this is the solution:

243=3^5
1125=(3^2)(5^3)
72=(2^3)(3^2)

now:

7(3^5/3)- (3^2/3)(5^3/3)+ 5(2^3/3)(3^2/3)=
7(3)(3^2/3)- (3^2/3)(5)+ 5(2)(3^2/3)

and now you can collect (3^2/3):
(3^2/3)[7*3-5+5*2]=
(3^2/3)[21-5+10]=
(3^2/3)(26)=26 cube root 9

so it's equal to
26(3^2/3) or 26 cube root 9

Answer 2

This still doesn't look very nice in the end! It's:

26*3^(2/3).

(Well, maybe that's not too bad; I've seen worse.)

For what it's worth, its value is therefore ~ 54.08218... .

First, let's express everything to be "cube-rooted" in terms of the respective and successively recognizable integer factors:

243 = 3 x 81 = 3 x 9 x 9 = 3^5;
1125 = 125 x 9 = 3^2 x 5^3; and
72 = 9 x 8 = 3^2 x 2^3.

So, 7cube root 243-cube root1125 +5 cube root 72

= 7 (3^5)^(1/3) - (3^2 5^3)^(1/3) + 5 (3^2 2^3)^(1/3)

= 7*3^(5/3) - 3^(2/3)*5 + 5*3^(2/3)*2

= (21 - 5 + 10)*3^(2/3) = 26*3^(2/3) = ~ 54.08218... .

As I said, not pretty, but perhaps not too bad.

Live long and prosper.

Answer 3

7 cube root 243-cube root 1125+5cube root 72
=7 cube root(3*3*3*3*3)-cube root(5*5*5*3*3)+5 cube root(2*2*2*3*3)
=7*3 cube root9-5 cube root9+5*2cube root 9
=21 cube root 9 -5 cube root 9 +10 cube root 9
=cube root 9(21-5+10)
=26 cube root 9 ans
t

Answer 4

21CUBE ROOT9 - 5CUBE ROOT9+10CUBE ROOT9
=17CUBE ROOT9

243=9*27 then cube root = 3 cube root 9