(D) The altitude of a small airplane in feet. 1, is a function of the time in seconds since the start of its descent, ar. The graph of the linear function passes through the points (6,650) and (8,600) 4) What is the equation of the function? y=-25x+800 4) What is the altitude of the airplane when it starts its descent? square feet

To find the equation of the linear function, we can use the slope-intercept form: $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept.<br /><br />Step 1: Find the slope ($m$) using the given points $(6,650)$ and $(8,600)$.<br />The formula for slope is: $m = \frac{y_2 - y_1}{x_2 - x_1}$<br /><br />Using the points $(6,650)$ and $(8,600)$:<br />$m = \frac{600 - 650}{8 - 6} = \frac{-50}{2} = -25$<br /><br />Step 2: Use one of the points and the slope to find the y-intercept ($b$).<br />We can use the point $(6,650)$:<br />$650 = -25(6) + b$<br />$650 = -150 + b$<br />$b = 650 + 150$<br />$b = 800$<br /><br />Step 3: Write the equation of the function.<br />The equation of the function is:<br />$y = -25x + 800$<br /><br />Answer 1: The equation of the function is $y = -25x + 800$.<br /><br />To find the altitude of the airplane when it starts its descent, we need to find the value of $y$ when $x = 0$.<br /><br />Step 4: Substitute $x = 0$ into the equation $y = -25x + 800$.<br />$y = -25(0) + 800$<br />$y = 800$<br /><br />Answer 2: The altitude of the airplane when it starts its descent is 800 feet.