Question

Which expression is equal to 4√20−3√45 ? −11√5, √5, 11√5, √-5

Answer 1

4√20 - 3√45
4√(4 * 5) - 3√(9 * 5)
8√5 - 9√5
-√5
It seems this is not one of your answer choices, but having checked it twice, I am sure it is the answer. Did you mistype your question or one of your answers?

Answer 2

Answer:

$4\sqrt{20} - 3\sqrt{45} = -\sqrt5$

Step-by-step explanation:

We are given the following information in the question:

We have to solve the given expression:

$4\sqrt{20} - 3\sqrt{45}$

We can solve the equation as :

$4\sqrt{20} - 3\sqrt{45}\\\\4\sqrt{2\times 2\times 5} - 3\sqrt{3\times 3\times 5}\\\\\text{Solving the square roots,}\\8\sqrt{5} - 9\sqrt{5}\\\\\text{Now, solving these like terms}\\(8-9)\sqrt5\\-1\sqrt5\\-\sqrt5$

Hence, the given expression is equal to $-\sqrt5$