Answer:
![\boxed{-3xy^{2}\sqrt [3] {2x^{2}}}](https://tex.z-dn.net/?f=%5Cboxed%7B-3xy%5E%7B2%7D%5Csqrt%20%5B3%5D%20%7B2x%5E%7B2%7D%7D%7D)
Step-by-step explanation:
Your expression is
![\sqrt [3] {-54x^{5}y^{6}}](https://tex.z-dn.net/?f=%5Csqrt%20%5B3%5D%20%7B-54x%5E%7B5%7Dy%5E%7B6%7D%7D)
Here's how I would simplify it.
![\begin{array}{rcll}\sqrt [3] {-54x^{5}y^{6}} & = & \sqrt [3] {(-1)^{3}\times 2 \times 27 \times x^{2} \times x^{3} \times y^{6}} & \text{Factored the cubes}\\& = & \sqrt [3] {(-1)^{3} \times 3^{3}\times x^{3} \times y^{6}\times 2 \times x^{2}} & \text{Grouped the cubes}\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcll%7D%5Csqrt%20%5B3%5D%20%7B-54x%5E%7B5%7Dy%5E%7B6%7D%7D%20%26%20%3D%20%26%20%5Csqrt%20%5B3%5D%20%7B%28-1%29%5E%7B3%7D%5Ctimes%202%20%5Ctimes%2027%20%5Ctimes%20x%5E%7B2%7D%20%5Ctimes%20x%5E%7B3%7D%20%5Ctimes%20y%5E%7B6%7D%7D%20%26%20%5Ctext%7BFactored%20the%20cubes%7D%5C%5C%26%20%3D%20%26%20%5Csqrt%20%5B3%5D%20%7B%28-1%29%5E%7B3%7D%20%5Ctimes%203%5E%7B3%7D%5Ctimes%20x%5E%7B3%7D%20%5Ctimes%20y%5E%7B6%7D%5Ctimes%202%20%5Ctimes%20x%5E%7B2%7D%7D%20%26%20%5Ctext%7BGrouped%20the%20cubes%7D%5C%5C%5Cend%7Barray%7D)
![\begin{array}{rcll}& = & \sqrt [3] {(-1)^{3} \times {3^{3}\times x^{3} \times y^{6}}} \times\sqrt [3] { 2 \times x^{2}} & \text{Separated the cubes}\\&=& \mathbf{-3xy^{2}\sqrt [3] {2x^{2}}} & \text{Took cube roots}\\\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcll%7D%26%20%3D%20%26%20%5Csqrt%20%5B3%5D%20%7B%28-1%29%5E%7B3%7D%20%5Ctimes%20%7B3%5E%7B3%7D%5Ctimes%20x%5E%7B3%7D%20%5Ctimes%20y%5E%7B6%7D%7D%7D%20%5Ctimes%5Csqrt%20%5B3%5D%20%7B%202%20%5Ctimes%20x%5E%7B2%7D%7D%20%26%20%5Ctext%7BSeparated%20the%20cubes%7D%5C%5C%26%3D%26%20%5Cmathbf%7B-3xy%5E%7B2%7D%5Csqrt%20%5B3%5D%20%7B2x%5E%7B2%7D%7D%7D%20%26%20%5Ctext%7BTook%20cube%20roots%7D%5C%5C%5Cend%7Barray%7D)
![\text{The simplified expression is $\boxed{\mathbf{-3xy^{2}\sqrt [3] {2x^{2}}}}$}](https://tex.z-dn.net/?f=%5Ctext%7BThe%20simplified%20expression%20is%20%24%5Cboxed%7B%5Cmathbf%7B-3xy%5E%7B2%7D%5Csqrt%20%5B3%5D%20%7B2x%5E%7B2%7D%7D%7D%7D%24%7D)
Total sets of 4-digits = 6
Total 4-digit numbers formed by one set of number = 4
So, total numbers that can be formed = 6 × 4 = 24
Answer:
81
Step-by-step explanation:
Let's do this systematically:
Four numbers: a, b, c, d
Whose mean is 85: 
Whose largest number is 97: 
Lets solve for the other numbers:
a+b+c+97 = 85*4 = 340
340 - 97 = 243
a+b+c = 243
at this point it doesn't matter what the numbers are, they just need to add up to 243.
We can do 243÷3=81, which is our answer
30=5(x+1)
30÷5=6
6=x+1
6-1=5
x=5