It would now cost $11. 45% of 20 is 9, therefore, you would subtract 9 from 20 (since it is getting marked down).
0.28=0.2+0.08
Or
0.28=2/10+8/100
Or
0.28=(2*1/10)+(8*1/100)
Or
0.28=(2*1/10^1)+(8*1/10^2)
3y = - 2x + 6
y = - 2/3x + 2
slope = - 2/3x
The Answer to your problem is:
0.66875
