RADIANT FLOOR HEATING SYSTEM

Math question please help me. Please show how to solve.?

Mr. Thomas is replacing the square tiles on his workshop floor. Each side of the new square tiles is 4 cm longer than the old. Each new tile will cover 72 square cm more than the old. How big are the old tiles?

Let x = the side length of the old tiles
Now x + 4 = the side length of the new tiles

The area of each tile is equal to the square of the length of its sides.

So:

(x+4)^2 = x^2 + 72
expanding the left side we get

x^2 + 8x + 16 = x^2 + 72
combining like terms we get

8x = 56
So

x = 7

The old tiles have a side length of 7 and therefore an area of 49 cm^2

The new tiles have a side length of 11 and therefore an area of 121 cm^2

Since 121 – 49 = 72 the solution checks.

Stoneridge