It means that value is not counted. it’s there but you don’t include it
Determine whether the point 1,5 is a solution to the system of inequalities below y>3x , y>/2x+1
Answer : -4a+10
Substitute (a-3) for x
-4(a-3)-2
-4a+12-2
-4a+10 but can also be written as -2(2a-5)
The 15 lbs at $7=$105
So multiple 5x9 as a test and check results. 105-45=60
Here you can see that 60 is a factor of 6 by 10 so you got lucky and got the answer of 10lbs at $6 & 5lbs at $9=15 lbs at $7 average
