9514 1404 393
Answer:
x = 1
Step-by-step explanation:
You can work this several ways.
1) Consider the factor that gets you from the y-value of the known pair to the y-value of the unknown pair. Here, that factor is -6/12 = -1/2.
Then the unknown value of x is the known value multiplied by that same factor:
x = (-1/2)(-2)
x = 1
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2) You can write the equation for a "varies directly" relationship and solve for the constant of proportionality. Then you can use that equation to find the unknown value of x.
y = kx . . . . . . . . . . . . . . y varies directly with x
k = y/x = 12/-2 = -6
Now we know ...
y = -6x
Filling in the new value for y, we have ...
-6 = -6x
1 = x . . . . . . divide by -6
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3) You can write a proportion. Since we want to find a value for x, it is convenient to put that in the numerator.
-2/12 = x/-6
Multiplying by -6, we get ...
(-6)(-2)/12 = x = 1
