The cost of meal = 
The tip to the waiter = 
%
Discount = 
%
Cost = 
Cost = 
Cost = $
0
1.65 + 0.85x= $20
0.85x=$18.35
x=21 10/17
first you write the equation
then you have to subtract 1.65 from the equation but you also have to subtract it from 20
then you divide 0.85 from 0.85x and from the 18.35 left over from subtracting 1.65 from 20
then you should get x=21 10/17 (simplified) but the decimal form is a ongoing fraction so you can just round it up to the nearest hundredth
Solutions just means the amount of times the lines intersect, so there are no solutions. Since the lines are parallel, they’re going the exact same direction forever and ever, never intersecting. Hope this helps!
Assuming 5a3 equals 5a^3, and the same for everything else, you would plug in 4 for a, so 5(4)^3 - 2(4)^2 + 4 - 45, which equals 247.
