It has no solution because x is always the same amount. So.. for example.
lets say x = 10.
then it would be 10 + 2 = 10 + 3.
12 doesnt = 13. :)
Find the rate of change, (y2-y1)/(x2-x1), from the data given...
(2.16-1.26)/(12-7)=0.18
(1.26-0.72)/(7-4)=0.18
Since the rate is constant, this is a linear equation of the form y=mx+b. Furthermore, since 0 pencils cost 0, b=0, so the cost of the pencils is simply the number of pencils times 18 cents...
c(p)=0.18p (cost with respect to pencils is 0.18 times the number of pencils)
*here is step by step*
(Remember to add the 'x' to the slope)
-4x+6y=16
6y=4x+16
y= 4/6x + 2.66
The complete answer is:
y= 2/3x + 2.66