Let's call our number <em>x</em>.
So we can setup the equation x² = 100.
To solve this equation, we square root both sides.
So we have x = ±10.
Always use plus or minus when square rooting both sides
of an equation so our answer is not only 10, it's also -10.
3000+200+60+4 I think would be the answer from what I remember
The law of cosines for this particular situation is b^2 = a^2 + c^2 - 2ac cosB.
Filling in what you know, you have b^2 = 25 + 49 - [2(5)(7)-.1908], which simplifies to b^2 = 74 - 69.8092 which gives you a b^2 value of 4.1908, but you have to take the square root of that so you get a side value for b of 2.05.