Aseven foot ladder, leaning against a wall, touches the wall x feet above the ground. write an expression (in terms of x) for the distance from the foot of the ladder to the base of the wall.

The ladder leaning against the wall forms a right angle triangle with the wall and the ground

The wall height = x
The ladder length = 7
The distance between the foot of the ladder to the wall = y

We will use Pythagoras theorem to find an expression for y

7² = x² + y²
y² = 7² - x²