Suppose y varies directly with x, and y = 7 when x = 3. What is the value of x when y = 28? If 7 = k (3) then 28 = k (x) Find x

Question

Mathematics

Rodolfo Greer

20 April, 20:15

Suppose y varies directly with x, and y = 7 when x = 3. What is the value of x when y = 28? If 7 = k (3) then 28 = k (x) Find x

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Holly Schwartz · Answer 1

Let y and x be the numbers that varies directly (that means they keep the same proportion)

Then we have 7y = 3x, OR y/x = 7/3 (this ratio should be kept for any value of x and y:

y/x = 7/3, if y = 28, then 28/x = 7/3 or x = (3) (28) / 7 = 12

SO X = 12