SOLUTION: I try to figure out this one but still don't get it. My answer still not match from the textbook. Please help! If each side of a square is increased by 5 cm, the total area of b

Algebra ->  Radicals -> SOLUTION: I try to figure out this one but still don't get it. My answer still not match from the textbook. Please help! If each side of a square is increased by 5 cm, the total area of b      Log On


   

Question 1066869: I try to figure out this one but still don't get it. My answer still not match from the textbook. Please help!
If each side of a square is increased by 5 cm, the total area of both the new square and the original square will be 200 cm2. Approximate to the nearest tenth of a centimeter the length of each side of the original square.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Again?
??

x%5E2%2B%28x%2B5%29%5E2=200
SOLVE FOR x. If you do it well, you should trust your efforts & your work.

x%5E2%2Bx%5E2%2B10x%2B25=200

2x%5E2%2B10x%2B25=200

2x%5E2%2B10x-175=0

Maybe factorable or maybe not. Use general solution to quadratic equation if you want to avoid trying to factorize.

Discriminant: 10%5E2-4%2A2%2A%28-175%29=100%2B8%2A175=1500

You want the PLUS form for x.
x=%28-10%2Bsqrt%281500%29%29%2F4

x=%28-10%2B10sqrt%2815%29%29%2F4

highlight%28x=%28-5%2B5%2Asqrt%2815%29%29%2F2%29