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Math·Algebra·Linear functions

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As a car approaches an intersection, a linear function $f$ models its speed, in miles per hour (mph), $x$ seconds after the brake is initially applied. According to the function, the car’s estimated speed is 23 mph when the brake is initially applied, and the car’s estimated speed decreases by 4.1 mph every second after the brake is initially applied. Which equation defines $f$?

A

$f(x)=23x$

B

$f(x)=4.1x$

C

$f(x)=-4.1x+23$

D

$f(x)=-23x+4.1$