Question

Simplify: 12√7 - 5√28

a. -8√7
b. 2
c. 2√7
d. 2√14

Answer 1

c

Answer 2

5√28 = 5*√4 * √7 = 10√7
so 12√7 - 5√28 = 12√7 - 10√7 = 2√7

Answer 3

\[\sqrt{28} = \sqrt{4*7} = \sqrt{4}\sqrt{7}=2\sqrt{7}\]