So first, you get the absolute value to one side:

Next, set up two equations; One where the value inside the absolute value lines is positive, and another where it is negative, and solve both for the variable:

Your answers are
8 and -8, or +-8.
For AD:
AD=root((c-0)^2 + (d-0)^2)=root((c)^2 + (d)^2)
For BC:
BC=root(((b+c) - b)^2+(d-0)^2)=root((c)^2+(d)^2)
For AB:
AB=root((b-0)^2 + (0-0)^2)=root((b)^2 + (0)^2)=root((b)^2)
For CD:
CD=root((c-(b+c))^2 + (d-d)^2)
CD=root((b)^2 + (0)^2)
CD=root((b)^2)
Answer:
<em>$2.29/gal</em>
Step-by-step explanation:
The unit price is in units of cost per volume, or dollars per gallon, so you divide the cost in dollars by the volume in gallons.
unit rate = ($18.32)/(8 gal) = $2.29/gal
1 is A - just plug and chug
2 is B - for 2 linear equations to have infinite solutions they mustbe the same
3 is C
4 is C - that is where they intersect
5 is A - same slope and different intercepts means no solutions