Multiply Radicals
How to multiply radicals: 2 examples and their solutions.
Example√6x × √3x3y
Combine 6x and 3x3y
in a square root sign.
So √6x × √3x3y = √6x⋅3x3y.
6 = 2⋅3
3⋅3 = 32
x⋅x3 = x1 + 3 = x4
Product of Powers
Change the factors of 2⋅32⋅x4⋅y to perfect squares
as much as you can.
32 is already a perfect square.
x4
= x2⋅2
= (x2)2
Power of a Power
Take the squared factors, 3 and x2,
out from the square root.
And leave the non-squared factors, 2 and y,
in the square root.
Simplify a Radical
So 3x2√2y is the answer.
Example(√3 + √2)(√6 - 2)
Use the FOIL method.
Multiply the first two terms: √3⋅√6.
Multiply the outer terms: √3⋅(-2) = -2√3.
Multiply the inner terms: +√2⋅√6.
Multiply the last two terms: +√2⋅(-2) = -2√2.
Split √6 into √3 and √2:
√6 = √3⋅√2.
√3⋅√3
= (√3)2
= 3
√2⋅√2
= (√2)2
= 2
Square Root
Cancel -2√3 and +2√3.
And 3√2 - 2√2 = √2.
So 3√2 - 2√3 + 2√3 - 2√2 = √2.
Add and Subtract Radicals
So √2 is the answer.