algebra

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I'm a little confused on how to solve this:

The number of cricket chirps per minute is given by
N(t) = 7.2t - 32
Where t is the temperature in degrees Celsius.

a. Graph the equation N(t) = 7.2t - 32

I have learned a few ways to graph equations. One way would be to use -32 as the y-intercept and from there go up 7.2, over 1, etc. The other way would be to pick an x, or in this case, t value, multiply it by 7.2, subtract 32, and that would be the y value. I have tried both ways and gotten different results, so which way would be correct?

Thank you very much! Any help is appreciated!

• algebra - ,

both ways are correct, you must have made an error

method 1 - slope y-intercept
one point is obviously (0,-32)
now from there go up 7.2 then to the right 1
this would give you (1,-24.8)
join these two points

method 2: finding random ordered pairs

let t = 1, N(1) = 7.2-32 = -24.8 -- (1,-24.8)
let t = 3 N(3) = -10.4 --- (3,-10.4)
join these points, bet you get the same line

• algebra - ,

Thank you so much!