203k views
5 votes
Hey can anyone help plz?

Which expression is equal to 2√28-5√63?
A.) √7
B.) -37√7
C.) -11√7
D.) -√7

1 Answer

3 votes

We have been given an expression
2√(28) -5√(63) and we are asked to find correct option from the given choices.

Let us simplify our expression.


2√(28) -5√(63)

First of all we will take out perfect squares from our radical.


2√(7\cdot4) -5√(7\cdot9)


2√(4) \cdot√(7) -5√(9) \cdot√(7)


2\cdot2√(7) -5\cdot3√(7)


4√(7) -15√(7)


-11√(7)

Our expression simplifies to
-11√(7), therefore, option C is the correct choice.

User Christopher Currie
by
8.6k points

Related questions

2 answers
5 votes
13.1k views
1 answer
1 vote
63.6k views