Question

ivan uses a transit card to pay for his bus fare. the table shows the amount of money left on the card, y, as a function of the number of rides ivan takes, x. write an equation to represent the amount of money left on the card, y. y = x + 30 an error has occurred. please enter a number. number of bus rides, x amount of money left on card ($), y 0 30 3 24 6 18 9 12

Explanation:

Step1: Find the slope

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. Let $(x_1,y_1)=(0,30)$ and $(x_2,y_2)=(3,24)$. Then $m=\frac{24 - 30}{3-0}=\frac{- 6}{3}=-2$.

Step2: Determine the equation

The equation of a line is in the form $y = mx + b$, where $m$ is the slope and $b$ is the y - intercept. We found $m=-2$ and from the table when $x = 0$, $y=30$ so $b = 30$. The equation is $y=-2x + 30$.

Answer:

$-2$