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

`4√(20) - 3√(45) = -\sqrt5`

Explanation:

We are given the following information in the question:

We have to solve the given expression:

`4√(20) - 3√(45)`

We can solve the equation as :

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

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