Find Slope of the Line

Set 1.6
Question 48

See attachment.

 

y-intercept is 6 => equal to the length of the height of the triangle
area=72
area of triangle :

area=(1/2)base*height ............ substitute given


72=(1/2)base*6
72=base*3
base=72/3
base=24

y-intercept is (0,6)
endpoint of the base is at (24,0)

slope m=(6-0)/(0-24)
m=6/(-24)
m=-1/4

 

How did you know what to do? All I see is a picture and a shaded triangular region.

 

when you see that given area of triangle, and you see y-intercept is 6, you know it's possible to calculate the length of other leg of triangle using formula for the area of triangle

 

This is obvious to you but not to most people.