SOLUTION: Now I am lost...please help me. Simplify by combining like terms: 63 square root symbol - 2 square root symbol 28 + 5 square root symbol 7

Algebra ->  Square-cubic-other-roots -> SOLUTION: Now I am lost...please help me. Simplify by combining like terms: 63 square root symbol - 2 square root symbol 28 + 5 square root symbol 7      Log On


   



Question 47406: Now I am lost...please help me.
Simplify by combining like terms:
63 square root symbol - 2 square root symbol 28 + 5 square root symbol 7

Answer by elima(1433) About Me  (Show Source):
You can put this solution on YOUR website!
If I am reading it the right way, it is;
First you need all of them to be like terms so you can add or subtract.
So, since 63 is not a perfect square you need to find the multiples that are.
63: 3, 7, 9, 12; 9 is a perfect square so; sqrt%289%2A7%29, now look at 2sqrt%2828%29, 28 is not a perfect square so find multiples that are; 2,4,7,14: 4 is or perfect square, so we have; 2sqrt%284%2A7%29, and finally 5sqrt%287%29,
7 is not a perfect square, but it does not have any multiples that are so we can not do anything to that. Now we have;
sqrt%289%2A7%29-2sqrt%284%2A7%29+5sqrt%287%29
find the square roots of the perfect squares;
sqrt%289%2A7%29, 9 is a perfect square = 3, sqrt%284%2A7%29, 4 is a perfect square=2; so now we have;
3sqrt%287%29-2%282%29sqrt%287%29+5sqrt%287%29, now you can add and subtract because they are like terms.
3-4+5=4; so the answer:
4sqrt%287%29
Hope you understand :)