radical problems i need help?

Question

i am lost on 3 of them

2a sqrt(2a^3)-3sqrt(8a^5)

a sqrt(9b)+3 sqrt(b^2)-sqrt(4a^2b)

a sqrt(9b)+3sqrt(b^2)-sqrt(4a^2b)

Answer 1

wow thats a big equation, sorry i can't help i am just going into the 8th grade. i just want to say, GOOD LUCK!

Answer 2

Well the first one gives me A=0. The second one I do not know how to finish but here's where I'm stuck:

9A^2b+9b^2+54AB^3=0 You have to elevate on each side by 2. Remember sqrt = the 1/2 of something. If you elevate by 2 it will be 1/2 times 2 which = 1 eliminating the sqrt.

The first one ends up like this and from here it gives me 0

[ (2A sqrt(2A^3) ] ^2= [ (3 sqrt8A^5) ] ^2
8A^5=72A^5
54A^5=0
a=0
Hope I was of some help

Answer 3

square root is just like the power of 1/2
swap all of those terms to that and maybe you can see what to do - use exponent rules - that could help

also use the fact that sqrt(a^2) = a
and sqrt(9a) = sqrt (9) * sqrt (a) = 3 sqrt(a)


a sqrt(9b)+3 sqrt(b^2)-sqrt(4a^2b)
3a sqrt (b) + 3 b - 4 sqrt(a^2b)
3a sqrt (b) + 3 b - 4 (a^2b)^.5 <----multiply exponents 2b*.5
3a sqrt (b) + 3 b - 4a^b


for the first one - are you sure it is not cubed root?
it may not be, but cubed root would make more sense (it would make it much easier)