Now that you know that one side of the big square is you know that
the area of the big square is
21 . B
When solving this equation algebraically, you will square both sides of
the equation, which can result in a false solution:
Try x = 4 and x = 9 in the original equation, and you’ll find that x = 4
doesn’t really work. The only solution is x = 9.
22 . E
Sketch a diagram. First the ball drops 10 meters and rebounds of that,
or 8 meters: