Answer: B
Step-by-step explanation: Best way to solve this is to first take the square root of 9 which is 3. Notice in the expression there is an x^4 but once the square root of 9x^4 is taken, you get 3x^2. There is a minus sign in the middle, so answer choice C and D are out. Now, there is answer choice A or B. Now we take the square root of 12 but 12 isn't a perfect square root. But, you can think of 2 numbers that when you multiply give you 12 and one of those numbers is a perfect square root. In this case, it would be 4 because 4 times 3 = 12. Square root of 4 is 2. Again, notice there is an x^2. Once the square root of 4 is taken, you are left with 2x and square root of 3. The square root of 3 isn't a perfect square root. But, you can write the expression in the following way:
2x[tex]\sqrt{3}[/tex] - 3[tex]x^{2}[/tex]
Hope this helps.
