SOLUTION: please help Multiplying radicals and simplify 1) (3 square2)(-4 square 10) 2)(3-2 square 7)(3 +2 square 7)

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Question 194357: please help Multiplying radicals and simplify
1) (3 square2)(-4 square 10)
2)(3-2 square 7)(3 +2 square 7)
Answer by orca(409) About Me  (Show Source):
You can put this solution on YOUR website!
1)
%283sqrt%282%29%29%28-4sqrt%2810%29%29
=3%2A%28-4%29sqrt%282%29%2Asqrt%2810%29
=-12sqrt%282%2A10%29
=-12sqrt%282%5E2%2A5%29
=-12%2A2%2Asqrt%285%29
=-24sqrt%285%29
2)
Use the formula %28a%2Bb%29%28a-b%29=a%5E2-b%5E2 to simplify
%283-2sqrt%287%29%29%283+%2B2sqrt%287%29%29
=3%5E2-%282sqrt%287%29%29%5E2
=9-2%5E2%2A%28sqrt%287%29%29%5E2
=9-4%2A7
=9-28
=-19