Chapter 14 - Sequences, Series, and the Binomial Theorem - 14.2 Arithmetic Sequences and Series - 14.2 Exercise Set - Page 903: 51

$y=\frac{1}{3}x+10$

In general, the equation of the line has form $y=ax+b.$ The coefficient $a$ is responsible for the slope of the straight line. In our case $a=\frac{1}{3}. $ Also we know the $y$-intercept $(0,10)$. We determine $b$: $10=\dfrac{1}{3}\cdot 0+b$ $b=10$ So $y=\frac{1}{3}x+10$