how do you solve 4x^(2/3)+16x^(1/3)=-15

Question

anonymous · Answer

try to move the 4 and the 16 to the other side of the = sign, for a start

anonymous · Answer

try to move the 4 and the 16 to the other side of the = sign, for a start

anonymous · Answer

actually thats a good question, i dont know how to do it. anyone?

anonymous · Answer

I got it, saw this in chat but idk why i cant join the chat. Anyone interested?

anonymous · Answer

yes!

anonymous · Answer

you let a=x^(1/3)
so equation becomes 4a^2+16a+15=0
solve that get a=-3/2 or a=-5/2
case 1: a=-3/2
so x^(1/3)=-3/2
x=(-3/2)^3
case 2: similar

anonymous · Answer

ok, but can you put a step in going from your 2nd line to the third? cause thats also getting me stuck

anonymous · Answer

ok

x^(2/3)=(x^(1/3))^2=a^2

4a^2+16a+15
=4a^2+6a+10a+15
=2a(2a^2+3) + 5(2a+3)
=(2a^2+3)(2a+5)
hope that's clear enough