Answer:
3√7
Step-by-step explanation:
(√3)(√21) = √(3·21) = √(3·3·7) = √(3²·7) = 3√7
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The product of the roots is the root of the product. The product, 3·21 = 63, has a square factor that can be removed from under the radical. You need to factor out the root of that square when you simplify the expression.
Answer:
3 square root of 7
Step-by-step explanation:
square root of 21 can also be written as square root of 3 * square root of 7
the square root of 3 that's outside multiplies with the new square root of 3 giving square root of 9 which is 3, so 3 square root of 7
