A family is traveling in a car at a constant average speed during a road trip. The function d(t)=70t+620 models the distance d, in miles, the family is from their house t hours after starting to drive on the second day of the road trip.A) At what average speed is the family's car traveling?-ExplainB) What is the distance between the family's house and the point where they started driving on the second day-Explain

Answer:A.  70 miles per hour B.  620 miles from homeStep-by-step explanation:This function is a linear equation, following the slope-intercept form of a line.  This standard form is y = mx + b, where m is the slope and b is the y-intercept.  The slope of a line is the rate at which the steepness of the line is changing.  The y-intercept is where the function is "starting".In our case, the number in the rate of change position is 70.  It is being multiplied by t.  If t = 1, that means that after 1 hour, we have gone 70 miles.  If t = 2, that means after 2 hours we have gone 140 miles.  If t = 3, that means that after 3 hours, we have gone 210 miles; etc.  That number in the slope position represents the rate at which you are traveling PER HOUR; the slope.The "starting" position of day 2 is found in the y-intercept.  Replacing x with 0, meaning NO time has gone by at all, at the beginning of the second day, we are starting 620 miles from home.