You want to rent a television Company A charges $50 per week plus a one-time fee

Company A: y = 50x + 15
Company B: y = 130x + 55

Set the equations equal to each other and solve for x (number of weeks).
50x + 15 = 130x + 55

Subtract 50x from both sides:
15 = 80x + 55

Subtract 55 from both sides:
-40 = 80x

Did you have a typo? The companies will never have the same cost because company B costs so much more and weeks cannot be negative.

104

Step-by-step explanation:

Let x = the unknown second number.  2/5 of [the sum of] two numbers is 56. One of the numbers is 36:

 

(2/5)(36+x) = 56

 

Multiply both sides by 5/2:

 

36 + x = 56*5/2

36 + x = 140

x = 104

 

Check:

(2/5)(36+104)=56

(2/5)(140)=556

280/5 = 56

56 = 56

Check!