add 3√21+7√21 1 point

multiple choice answers-
10√21.
10√42.
√24+√28.
√52

The sum of 3√21 and 7√21 is 10√21.

add √19+√19

√20
2√38
2√19
√40

The sum of √19 + √19 is 2√19.

add ^3√22+3√22+√22

5√22
3^√22 +4√22
5√66
3^√22+4√44

The sum of ^3√22 + 3√22 + √22 is 5√22.

subtract 8√23-√23

8√46
7√46
8√23
7√23

The subtraction of 8√23 - √23 is 7√23.

Jake runs 7√6 miles on monday and 5√6 on tuesday.What is the difference in milles run each day.

4√6
4√12
2√12
2√6

The difference in miles run each day is 2√6 miles.

To add the expressions 3√21 and 7√21, you can combine the like terms. In this case, √21 is the common term.

To add the coefficients (numbers) in front of the square roots, you simply add them together.

2√21 + 7√21 = (3+7)√21 = 10√21.

Therefore, the correct answer is 10√21.