Write an equation for the linear function and use it to answer the given question.
-Normaltown High School's pool record for the 100-yard freestyle was 47.8 in 1990. Assume that the record falls at a constant rate of 0.03 second per year. What does the model predict for the
Record in 2010?
A) $R = 47.8 t + 0.03 ; 956.03$ seconds
B) $\mathrm { R } = 47.8 \mathrm { t } - 0.03 ; 955.97$ seconds
C) $\mathrm { R } = 47.8 + 0.03 \mathrm { t } ; 48.40$ seconds
D) $R = 47.8 - 0.03 \mathrm { t } ; 47.20$ seconds

Question

Write an equation for the linear function and use it to answer the given question.
-Normaltown High School's pool record for the 100-yard freestyle was 47.8 in 1990. Assume that the record falls at a constant rate of 0.03 second per year. What does the model predict for the
Record in 2010? 
A) $R = 47.8 t + 0.03 ; 956.03$ seconds
B) $\mathrm { R } = 47.8 \mathrm { t } - 0.03 ; 955.97$ seconds
C) $\mathrm { R } = 47.8 + 0.03 \mathrm { t } ; 48.40$ seconds
D) $R = 47.8 - 0.03 \mathrm { t } ; 47.20$ seconds

Quizplus · Accepted Answer

The correct equation to model the situation is $R = 47.8 - 0.03t$, where $t$ is the number of years since 1990. For 2010, $t = 20$, so the record would be $47.8 - 0.03(20) = 47.20$ seconds.

Write an Equation for the Linear Function and Use It R=47.8t+0.03;956.03R = 47.8 t + 0.03 ; 956.03R=47.8t+0.03;956.03

Write an Equation for the Linear Function and Use It $R = 47.8 t + 0.03 ; 956.03$