For this case we have the following equations:
y = 60x + 40
y = 50x + 80
Equaling both equations we have:
60x + 40 = 50x + 80
From here, we clear the value of x:
60x - 50x = 80 - 40
10x = 40
x = 40/10
x = 4 weeks
Substituting x = 4 in any of the equations we have:
y = 60 (4) + 40
y = 240 + 40
y = 280 $
Answer:
$ 280 4 weeks
Let the number of History books be x. Then:-
x + x - 59 = 343
2x = 402
x = 201
So there are 201 History books and (201 - 59) = 142 Chemistry books.
Using the pythagras theorem :
Length of rope = sqrt (6^2 - 5^2) sqrt 11 = 3.32 feet to nearest hundredth.
