I'm working on a question where I got the second part of it but not the first. The second part asks to prove a y-intercept given y= # and x= #. I got the answer for that, but I'm stuck on the first part in terms of I'm not sure what it's asking! The question says: The graph y= f(x) is a straight line with slope -2/3. If x changes by -12 what is the change in f(x)? Is this a translation, where the line is moving -12 places? Or something else? Thanks in advance!
Slope and Changes in X
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algebra-precalculus
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1It means: if you have a point on the line $(x,y)$ and you shift $x$ by $-12$, how much must you also shift the $y$ coordinate for the destination point to be on the line as well? You can use geometry to intuitively help you solve this by drawing a right triangle with the hypotenuse as part of the line and base length 12. Also, I don't think negative exponents are relevant here. – 2011-09-15
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0I know, I was asking another question before but exited because I figured it out :) Thanks I'll give that a try – 2011-09-15
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0You can also use the formula for slope: $m=\Delta y / \Delta x$, plugging in $m=-2/3$ and $\Delta x = -12$. Does this sound familiar at all? – 2011-09-15
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0Yes it does... I really should have known/thought of that, actually. Thank you! – 2011-09-15