√21√3+√14

To simplify the expression √21√3 + √14, we can first simplify the square roots and then add the resulting terms together.

First, let's simplify each square root:
√21 can be simplified as √(7*3), which is √7√3.
√14 can be simplified as √(7*2), which is √7√2.

Now we can rewrite the expression:
√21√3 + √14 = √7√3√3 + √7√2.

Since √3√3 is equal to √(3*3), which simplifies to 3, and √2 is already in its simplified form, the expression becomes:
√7(3) + √7(√2) = 3√7 + √7√2.

Now we can combine the like terms:
3√7 + √7√2 = (3 + √2)√7.

Therefore, the simplified expression is (3 + √2)√7.