14. 2x-1 = 0, x+7=0
x = 1/2, x = -7
15. x^2 + 3x - 10 = 0
(x + 5)(x - 2) = 0
x = -5, x = 2
16. x^2 - 25 = 0
(x-5)(x+5)
x = 5, x = -5
120 inches.
This is because to find the scale factor, you have to take the square root of the area scale. This will give you 30-1 ratio. Then multiply the 4 by that number.
One answer (of several) would be 33: It's between 10 and 200 and the sum of its digits is 6. Continue this same pattern to identify other answers.
