SOLUTION: a floor can be covered with 1,728 small square tiles. if tiles 2 inches longer on each side are used, the floor can be covered with 432 tiles. find the length of each side of the s

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: a floor can be covered with 1,728 small square tiles. if tiles 2 inches longer on each side are used, the floor can be covered with 432 tiles. find the length of each side of the s      Log On


   



Question 741096: a floor can be covered with 1,728 small square tiles. if tiles 2 inches longer on each side are used, the floor can be covered with 432 tiles. find the length of each side of the smaller tile.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x = side length of the smaller tile
1728*x^2 represents the area of this floor.

The other tile sized at x+2, covered that same area and this area expressible as 432*(x+2)^2 using these larger tiles.

Same area! 1728x%5E2=432%28x%2B2%29%5E2.
Find x.


Plenty of ways to make mistakes in solving that equation. Misfactoring, transposing an incorrect number, sign mistake,...


1728x%5E2=432%28x%2B2%29%5E2
4x%5E2=%28x%2B2%29%5E2
4x%5E2=x%5E2%2B4x%2B4
3x%5E2-4x-4=0, factorable, but,....

x=%284%2Bsqrt%2816-4%2A3%2A%28-4%29%29%29%2F%282%2A3%29, direct use of quadratic formula solution
x=%284%2B8%29%2F%286%29
highlight%28x=2%29


For factoring starting from the simplified quadratic equation,
3x%5E2-4x-4=%283x%2B2%29%28x-2%29=0
Take the positive root, x=2.