The correct expression that is equal to (2√28 - 5√63) is;
Option D; -11√7
The correct question is;
Which expression is equal to 2√28 - 5√63
The correct options are in the link at the end of this answer.
The given expression is in surd form. To solve it, we first have to break down the numbers inside the square roots into a product of two numbers with one of the numbers being a perfect square.
We know that;
28 can be expressed as 7 × 4 = 28
Also; 63 can be expressed as 7 × 9 = 63
Thus;
2√28 - 5√63 will be written as; 2√(7 × 4) - 5√(9 × 7)
From product law of surds, we know that;
√(a × b) = √a × √b
Thus, our expression is;
2(√4 × √7) - 5(√9 × √7)
⇒ 2(2√7) - 5(3√7)
⇒ 4√7 - 15√7
Factorize √7 out to get;
(4 - 15)√7
⇒ -11√7
Read more at; https://brainly.com/question/13937081
