Tori has a cell phone plan that charges $0.09 for each text message sent. tori plans to spend no more than $40 per month on her texting bill. if c(t)=0.09t represents the total phone bill based on the number of texts (t) that tori sends each month, what is the domain of the function?

Where m is the slope of the line and b is the y-intercept of the line, or the y-coordinate of the point at which the line crosses the y-axis. to write an equation in slope-intercept form, given a graph of that equation, pick two points on the line and use them to find the slope. this is the value of m in the equation.