You see the 2 squares or whatever multiply them one by one so
Answer: 2
8 to the power of 1/3 is 2.
Step-by-step explanation:
Let
x-------> the first number
y------> the second number
we know that


equation 

equation 
substitute equation 1 in equation 2

using a graph tool-----> to resolve the second order equation
see the attached figure
the solution is

The problem gives you X, so replace X witht he given vaule and solve for y:
y = -0.1x^2 + 4X
X = 40
y = -0.1(40)^2 +4(40)
y = -0.1(1600) + 160
y = -160 + 160
y = 0