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# What's √12 + √75

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. Need full explanation i know the answer is 7√3 but i don't know how it is that. Can you help me and show the working out and how you get the answer.
2. Find factors of 12 and factors of 75 and split the roots. Then you can calculate the rest.
3. Root 12 = Root 4*Root3
4 is a square number so root 4 = 2
This means that Root 12 = 2*root3 or 2root3

root 75 = R25*R3
root 25 = 5
5*root3 = 5root3

2root3 + 5root 3 = 7root3 (keep the root3 the same and add then multiples).

When doing stuff like this, I look for square numbers that will go into them and try to make sure that if it does, then the part in the root is the same. In this case, they both have root3 so you can easily add the multiples together.
4. (Original post by UWS)
Find factors of 12 and factors of 75 and split the roots. Then you can calculate the rest.
Oh ok thx
5. (Original post by Kiritsugu)
Root 12 = Root 4*Root3
4 is a square number so root 4 = 2
This means that Root 12 = 2*root3 or 2root3

root 75 = R25*R3
root 25 = 5
5*root3 = 5root3

2root3 + 5root 3 = 7root3 (keep the root3 the same and add then multiples).

When doing stuff like this, I look for square numbers that will go into them and try to make sure that if it does, then the part in the root is the same. In this case, they both have root3 so you can easily add the multiples together.
Thank you. Now i understand it

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