A(h)=4h+70, A(h)=dollars to rent for h hours, h=hours rented.
B(h)=5h+60, same variable explanations...
....
To compare the two values at 6 hours you have:
A(6)=4(6)+70=24+70=$94
B(6)=5(6)+60=30+60=$90
So at 6 hours Company B would charge $4 less than Company A
...
Savings at 7 hours of rental by using B instead of A is:
S(h)=A(h)-B(h)
S(h)=4h+70-5h-60
S(h)=-h+10
S(7)=-7+10=$3
So at 7 hours, Company B saves you $3.
Set it up:
13 -27
---- x ----
2 8
then make the bottom numbers the same:
52 -27
---- x ----
8 8
After this you just multiply:
-1404 -351
--------- = ---------
64 16
thats the final answer
3x + 4 = 10..subtract 4 from both sides
3x = 6....subtraction property of equality
6
If you subtract it from two or 14 from eight or 24 or 26 for 20 can all see that they are subtracted by six
