SOLUTION: What is the y-intercept of -1/6(y+3)=(1/2)^x-3???? I think the answer is (0,-51) BUT I am not sure :(

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: What is the y-intercept of -1/6(y+3)=(1/2)^x-3???? I think the answer is (0,-51) BUT I am not sure :(      Log On


   

Question 138818: What is the y-intercept of -1/6(y+3)=(1/2)^x-3???? I think the answer is (0,-51) BUT I am not sure :(
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
What is the y-intercept of -1/6(y+3)=(1/2)^x-3???? I think the answer is (0,-51) BUT I am not sure :(

I can't tell whether you mean

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E%28x-3%29

or

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5Ex-3

--------------

If it was supposed to be this: 

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E%28x-3%29

then we substitute 0 for x

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E%280-3%29

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E%28-3%29

%28-1%2F6%29%28y%2B3%29=%282%2F1%29%5E3

%28-1%2F6%29%28y%2B3%29=2%5E3

%28-1%2F6%29%28y%2B3%29=8

Multiply both sides by -6%2F1

%28-6%2F1%29%28-1%2F6%29%28y%2B3%29=%28-6%2F1%298

1%28y%2B3%29=-48

y%2B3=-48

y=-48-3

y=-51

So the y-intercept is %28matrix%281%2C3%2C0%2C%22%2C%22%2C-51%29%29

???? I think the answer is (0,-51) BUT I am not sure :(

It looks as though you are right if it supposed to be

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E%28x-3%29

--------------------------------

But if it's supposed to be 

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5Ex-3

then we substitute 0 for x

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5E0-3

%28-1%2F6%29%28y%2B3%29=1-3

%28-1%2F6%29%28y%2B3%29=-2

Multiply both sides by -6%2F1

%28-6%2F1%29%28-1%2F6%29%28y%2B3%29=%28-6%2F1%29%28-2%29

1%28y%2B3%29=12

y%2B3=12

y=12-3

y=9

So the y-intercept is %28matrix%281%2C3%2C0%2C%22%2C%22%2C9%29%29

That's what it should be if it supposed 
to be

%28-1%2F6%29%28y%2B3%29=%281%2F2%29%5Ex-3

Edwin