You have to isolate x. First you start off by adding the like terms which is -3x and -x. By adding them you get -4x.
8 - 4x = 12
Then you subtract 8 on both sides since it is positive to isolate x.
-4x = 4
Then you divide -4 by both sides and get x=4/-4
4/-4 is simplified to -1 so the answer is x= -1
Since the two numbers vary directly, if Y is quadrupled, X will do the same. 2 times 4 is 8, 15 times 4 is 60.
X = 60.
Hope that helps!! :)
Answer:
y = 250x + 1500
Step-by-step explanation:
Slope is 250
y-intercept = 3000 - 6 × slope
3000 - 1500 = 1500
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