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Zorluk: OrtaSolving Systems of Linear Equations

A logistics team is packing a shipment containing standard crates and heavy crates. A load of 44 standard crates and 33 heavy crates weighs a total of 170170 pounds. Another load consisting of 22 standard crates and 55 heavy crates weighs a total of 190190 pounds. Based on this information, what is the weight, in pounds, of a single heavy crate?

Cevap: 30 pounds

Cevap

30
The correct answer is found by translating the word problem into the system of equations 4x+3y=1704x + 3y = 170 and 2x+5y=1902x + 5y = 190. By multiplying the second equation by −2-2, the xx terms are eliminated when the equations are added, yielding −7y=−210-7y = -210, which simplifies to y=30y = 30.

Adım Adım Çözüm

1
Define variables for the unknown quantities.
Let xx be the weight of a standard crate and yy be the weight of a heavy crate.
To translate the word problem into a mathematical system of equations.
2
Set up a system of linear equations based on the given information.
Equation 1: 4x+3y=1704x + 3y = 170
Equation 2: 2x+5y=1902x + 5y = 190
To mathematically represent the total weights of the two different loads.
3
Use the elimination method to cancel out the xx variable. Multiply Equation 2 by −2-2.
−2(2x+5y)=−2(190)⇒−4x−10y=−380-2(2x + 5y) = -2(190) \Rightarrow -4x - 10y = -380
Creating a −4x-4x term allows the xx variables to be eliminated when added to the 4x4x in Equation 1.
4
Add the new Equation 2 to Equation 1.
(4x+3y)+(−4x−10y)=170−380⇒−7y=−210(4x + 3y) + (-4x - 10y) = 170 - 380 \Rightarrow -7y = -210
This leaves a single-variable equation that can be directly solved.
5
Solve for yy.
y=−210−7=30y = \frac{-210}{-7} = 30
To isolate yy, which represents the target value: the weight of the heavy crate.

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Solving Systems of Linear Equations
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