Question

Which choice is equivalent to the expression below when x  0?

√18X^30-√9X^3+3√X^3-√2X^3

A.2√2X
B.4√X
C.2X√2X
D.√10X^3

Answer 1

`√(18x^3)-√(9x^3)+3√(x^3)-√(2x^3)=\\ 3√(2x^3)-3√(x^3)+3√(x^3)-√(2x^3)=\\ 2√(2x^3)=\\ 2x√(2x)\Rightarrow C`

Answer 2

`√(18x^3)-√(9x^3)+3√(x^3)-√(2x^3)\\\\=√(9x^2\cdot2x)-√(9x^2\cdot x)+3√(x^2\cdot x)-√(x^2\cdot2x)\\\\=3x√(2x)-3x√(x)+3x√(x)-x√(2x)=2x√(x)\\\\Answer:C.`