Answer:
- large: 40 lbs
- small: 20 lbs
Step-by-step explanation:
A system of equations can be written for the weights of the boxes based on the relationships given in the problem statement. One equation will be for the total weight of 1 large and 1 small box; the other will be for the total weight of 70 large and 60 small boxes.
Let L and S represent the weights of Large and Small boxes, respectively. The system of equations is ...
L + S = 60 . . . . . . combined weight is 60 lbs
70L +60S = 4000 . . . . weight of boxes in the truck
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We can solve this by substituting for s in the second equation.
70L +60(60 -L) = 4000
10L = 400 . . . . . . . . . subtract 3600, simplify
L = 40
S = 60 -L = 20
A large box weighs 40 pounds; a small box weighs 20 pounds.
Answer:
2.89
Step-by-step explanation:
Note the equal sign, what you do to one side of the equation, you do to the other. To solve, do the opposite of PEMDAS. Isolate the variable, z.
First, subtract 12 from both sides:
25 = 4.5z + 12
25 (-12) = 4.5z + 12 (-12)
25 - 12 = 4.5z
13 = 4.5z
Isolate the variable, z. Divide 4.5 from both sides:
(13)/4.5 = (4.5z)/4.5
z = 13/4.5
z = ~2.89 (rounded).
2.89 is your answer.
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