Question 737441
first remember that the sqrt (x*y) = sqrt (x) * sqrt (y)

we are given

2*sqrt(20*x) + sqrt(80*x) - 6*sqrt(125*x)   NOTE that I assume you meant for the x variable to be within the sqrt sign

using the rule of multiplying sqrt's above, we get

2*sqrt(20)* sqrt(x) + 3*sqrt(80)*sqrt(x)-6*sqrt(125)*sqrt(x)

evaluate the sqrt's of the real numbers, we get

2*4.47*sqrt(x) + 3*8.94*sqrt(x) - 6*11.18*sqrt(x)

multiply the real numbers, we get

8.94sqrt(x) + 26.82sqrt(x) - 67.08sqrt(x)

combine the like terms and we get

-31.32sqrt(x)