400000 10 to the fifth power is 100000, so when you switch out the 1 for a 4, it become 400000.
Notice the picture below, see the length "l"?
well

solve for "w", to find the width,
what's the length? well, l = 11/4 w
Just multiply 11 1/8 by 2 and u should get 22.25 so the length of UV is 22.25 inches
Cross multiplying we get
x^2 = 2*7x
x^2 = 14x
x^2 - 14x = 0 is the answer