C= 20-0.75x
c= 20-0.75(9)
c= 20-6.75
c= 13.25
Here c is the amount of change and x is the number of books bought.
The customer's change will be $13.25
If treasure is midway of two points then treasures point is(x1+x2/2,y1+y2/2)
16+3/2, 21+2/2
Else any point shown byyour options is treasure's point
Its asking to find an answer between 9 and 7 so the answer would be 8
Answer:
The equation of the sraight line 3x- y+ 6 =0
Step-by-step explanation:
<u><em>Explanation:-</em></u>
Given that the gradient of the function
|gradf| = 3 and point (-1,3)
Given that the slope of the line
m = 3
The equation of the straight line passing through the point(-1,3) and slope m =3

y-3 = 3(x-(-1))
y-3 = 3x+3
3x +3-y+3=0
3x- y+ 6 =0
<u><em>Final answer:-</em></u>
The equation of the sraight line 3x- y+ 6 =0
<u><em></em></u>
Answer:
I don’t understand the question
Step-by-step explanation: