If k > 0, x + 2k = y, and y + 5k = z, what is the ratio between z - x and y - x ? Choose the correct option
A) 3 to 1 B) 3 to 2 C) 4 to 3 D) 7 to 2 E) 5 to 3
y-x = 2k   z-y = 5k   Let's add the two equations together:   z-x = 7k   The ratio of z-x to y-x is 7:2.   The answer is 7 to 2.
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If k > 0, x + 2k = y, and y + 5k = z, what is the ratio between z - x and y - x ?