How??

If y varies directly with x and y = -7 when x = -1, find x when y = -84.

Find the rate of change for 2000 to 2010 given these ordered pairs in the data set: (2000, 286) and (2010, 192). Write your answer as a decimal.

Question

How??

If y varies directly with x and y = -7 when x = -1, find x when y = -84.

Find the rate of change for 2000 to 2010 given these ordered pairs in the data set: (2000, 286) and (2010, 192). Write your answer as a decimal.

mertsj · Answer

$$y=kx$$
$$-7=k(-1)$$
$$k=7$$
$$y=7x$$
$$-84=7x$$
$$-12=x$$

mertsj · Answer

For the second question:  to find the slope, subtract the y values  then subtract the x values.
Put the first number over the second number.  That is the slope.

mertsj · Answer

(286-192)/(2000-2010)=94/-10=47/-5