Understanding:
[Q4] Slope intercept form is [tex]y=mx+b[/tex], where m is slope and b is the y-intercept. We calculated the slope in the previous question which was -45. We can find b by using any point on the previous table and replacing it's x and y values, for this example, I'm going to use (0,1080).
[tex]y=mx+b\\1080=-45(0)+b\\b=1080[/tex]
Now, we can rewrite the equation as follows
[tex]y=-45x+1080[/tex]
[Q5] To find the y-intercept we simply replace every x value with a 0,
[tex]y=-45x+1080\\y=-45(0)+1080\\y=1080[/tex]
This means the y-intercept is at [tex](0,1080)[/tex].
For the x-intercept, you replace the y value with a 0 and solve for x,
[tex]y=-45x+1080\\0=-45x+1080\\-1080=-45x\\x=24[/tex]
This means the x-intercept is at [tex](24,0)[/tex].
Solutions:
[Q4] [tex]y=-45x+1080[/tex]
[Q5] x-intercept: [tex]x=24[/tex]; y-intercept: [tex]y=1080[/tex]
[Q6] The x-intercept represents the months it takes Philip to fully pay his friend for the car. The y-intercept represents the total amount Philip had to pay his friend.
