Let 
be the short, medium and long side, respectively. If we translate all the information into formulas, we get the following system:
Using the second equation, we can express the middle side in terms of the small one, and reduce the system to two equations in two unknowns:
And thus
But then again, using the first equation, the third becomes
So, the longest side is 12. Since the small is half the long, we have 
. Finally, the medium is three more of the small, so we have 
Answer:
x= 4
Step-by-step explanation:
simple math
48/12 = x
x= 4
The equation can be used to determine t, the weight of the textbooks is t = 0.7w
Given:
let
Total weight = w
Weight of notebook = n
Weight of backpack = b
Weight of textbook = t
w = n + b + t
where
n = 4 pounds
b = 2 pounds
t = 0.7w
So
w = 4 + 2 + 0.7w
w - 0.7w = 4 + 2
0.3w = 6
w = 6/0.3
w = 20
Recall,
t = 0.7w
= 0.7(20)
= 14 pounds
Therefore, the weight of the textbook is 14 pounds
Learn more about equation:
brainly.com/question/4916384
#64
Let x represent the time spent for valleyball
Then swimming will be 2x
x + 2x = 4.5
3x = 4.5
x = 4.5/3
x = 1.5
Time spent on valleyball: 1 1/2 hours
Time spent on swimming: 3 hours
