Simplify:

square root of 3 times square root of 21

square root of 24

square root of 63

3 square root of 7

none of the above

Answer

3 square root of 7

Explanation

square root of 3 times square root of 21

√3 × √21 = √(3×21)

                  = √63

                  = √(9×7)

                  = √9 × √7

                    = 3 × √7

                   = 3√7

The answer is 3 square root of 7

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer

step-by-step explanation: