If anyone can help me with this, it'd be greatly appreciated. Thank you.
2007-04-26 17:32:45 · 8 answers · asked by sonne_engel 1 in Science & Mathematics ➔ Mathematics
If y varies directly as x, then y = k*x, where k is the constant of variation.
In order to find the value of y that you want, you need an x value and k. Fortunately, you have a pair of related values, x = 18 and y = 36.
So, 36 = k* 18, and therefore, k = 2.
So, when x = 20, y = k*x = 2*20 = 40.
2007-04-26 17:38:04 · answer #1 · answered by polymac98 2 · 0⤊ 0⤋
40
2007-04-27 05:02:17 · answer #2 · answered by Rishu 1 · 0⤊ 0⤋
Directly proportional means they increase (or decrease) at the same rate.
y is twice the size of x
so if x is 20, y would be
40.
You can also set up a proportion:
y x
---- = ------
36 18
So 18y = 36x
or y = 2x
Then you can substitute in your x value:
y = 2(20)
y = 40
2007-04-27 00:34:40 · answer #3 · answered by cat n 3 · 0⤊ 0⤋
y=40
2007-04-27 00:36:04 · answer #4 · answered by Jess2424 3 · 0⤊ 0⤋
y = k x
36 = 18 k
k = 2
y = 2 x 20
y = 40
2007-04-27 07:53:23 · answer #5 · answered by Como 7 · 0⤊ 0⤋
well 36 is 2 times 18
so y = 2x
if x is 20
y is 2 times 20
or 40
2007-04-27 00:37:45 · answer #6 · answered by Campbell Gramma 5 · 0⤊ 0⤋
find the ratio between y and x
36 / 18 = 2
therefore y = 2x
x = 20, y must = 40
2007-04-27 00:36:32 · answer #7 · answered by (+_+) B 4 · 0⤊ 0⤋
y=(20*36)/18
y=720/18
y=40
2007-04-27 00:40:08 · answer #8 · answered by zulendy 1 · 0⤊ 0⤋