Answer:
27,0 the distance away from the school
Step-by-step explanation:
Apply the formula for equation of a straight line;
y=mx+c where c is the y intercept , and m is the gradient
From the graph, the slope is negative where speed decreases with increase in time
Find the gradient by applying the formula;
![m=\frac{y_2-y_1}{x_2-x_1}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7By_2-y_1%7D%7Bx_2-x_1%7D)
Taking y₁=24, y₂=20, x₁=9, x₂=12
Then;
![m=\frac{20-24}{12-9} =\frac{-4}{3}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B20-24%7D%7B12-9%7D%20%3D%5Cfrac%7B-4%7D%7B3%7D)
write the equation of the function as ;
y=mx+c, c=36( the y-intercept when x=0) hence the equation is;
![y=mx+c\\\\y=\frac{-4}{3}x+36](https://tex.z-dn.net/?f=y%3Dmx%2Bc%5C%5C%5C%5Cy%3D%5Cfrac%7B-4%7D%7B3%7Dx%2B36)
To get x-intercept, substitute value of y with 0
![y=mx+c\\\\\\y=-\frac{4}{3} +36\\\\\\0=-\frac{4}{3} x+36\\\\\frac{4}{3}x =36\\\\\\4x=36*3\\\\\\x=108/4=27](https://tex.z-dn.net/?f=y%3Dmx%2Bc%5C%5C%5C%5C%5C%5Cy%3D-%5Cfrac%7B4%7D%7B3%7D%20%2B36%5C%5C%5C%5C%5C%5C0%3D-%5Cfrac%7B4%7D%7B3%7D%20x%2B36%5C%5C%5C%5C%5Cfrac%7B4%7D%7B3%7Dx%20%3D36%5C%5C%5C%5C%5C%5C4x%3D36%2A3%5C%5C%5C%5C%5C%5Cx%3D108%2F4%3D27)
This means that the x-intercept is 27 ,and this means you will require 27 minutes to cover the whole distance to the school.