Remember
xyz=(x)(y)(z)
if x and y and z are all perfect cubes, xyz is also a perfect cube
remmeber
(x^n)^m=x^(mn)
so if it is perfect cube it can be factored into
(x^n)^3, such taht n is a whole number
basiclaly, see if the expoent is divisble by 3
all of them should be perfect cubes
215x^18y^3z^21
split them up to see which ones need changing
215=5*43, not a perfect cube
could be changed to 6^3, which is 216
x^18=(x^6)^3
y^3=y^3
z^21=(z^7)^3
the 215 needs to be changed
Answer:

Step-by-step explanation:
Remember 
You are given the fraction 
First, multiply the numerator and the denominator by -2-3i:

This gives you 13 in denominator, now multiply two complex numbers in numerator:

Thus, the initial fraction is

Answer:
the answer is D. there are infinite solutions to the system
Step-by-step explanation:
just took the test
Answer:
Step-by-step explanation:
U have to multiply 49 by 49 and then subtract 9