Hello from MrBillDoesMath!
Answer:
y = -6x + 360
Discussion:
Suppose that y = mx + b. From the first table row when x = 0, y = 360. Substituting these in the equation gives
y = mx + b
360 = m(0) + b => b = 360
So far then y = mx + 360. From the second row of the table
we know that y = 300 when x = 10. Substituting this in y = mx + 360 gives
y = mx + 360
300 = m(10) + 360 =>
300 - 360 = 10m =>
-60 = 10m =>
m = -6
Conclusion: the equation is y = -6x + 360
BUT we should substitute the values from the other rows into this equation to make sure the data provided is linear. (Remember: table data can lie. Only MrBill doesn't lie! );
3rd row: Does 240 = -6(20) + 360 = -120 + 360 - 240 . Yes
4th row: Does 180 = -6(30) + 360 = -180 + 360 = 180. Yes
5th row: Does 120 = -6(40) + 360 = -240 + 360 = 120. Yes
Thank you,
MrB
