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Zorluk: OrtaSystems of Linear Equations

A landscaping company sells two types of soil mixtures: a basic mixture and a premium mixture. Each bag of basic mixture contains 44 pounds of compost and 88 pounds of sand. Each bag of premium mixture contains 66 pounds of compost and 55 pounds of sand. A landscaper purchases a combination of bags containing a total of 4646 pounds of compost and 5757 pounds of sand. How many bags of premium mixture did the landscaper purchase?

Cevap: 5 bags

Cevap

5
The system of equations representing the scenario is 4b+6p=464b + 6p = 46 for compost and 8b+5p=578b + 5p = 57 for sand, where bb represents the number of bags of basic mixture and pp represents the number of bags of premium mixture. Multiplying the first equation by 22 gives 8b+12p=928b + 12p = 92. Subtracting the second equation from this yields (8b+12p)(8b+5p)=9257(8b + 12p) - (8b + 5p) = 92 - 57, which simplifies to 7p=357p = 35. Dividing by 77 gives p=5p = 5. Thus, the landscaper purchased 55 bags of premium mixture.

Adım Adım Çözüm

1
Define variables and write the system of equations based on the given context.
Let bb represent the number of basic mixture bags and pp represent the number of premium mixture bags. The system is:
4b+6p=468b+5p=57\begin{aligned} 4b + 6p &= 46 \\ 8b + 5p &= 57 \end{aligned}
Translating the word problem into a system of linear equations is necessary to solve for the unknowns.
2
Multiply the first equation by 22 to facilitate the elimination method.
8b+12p=928b + 12p = 92
Aligning the coefficients of bb allows us to eliminate bb by subtracting the two equations.
3
Subtract the second equation from the new equation.
(8b+12p)(8b+5p)=9257    7p=35(8b + 12p) - (8b + 5p) = 92 - 57 \implies 7p = 35
This isolates the variable pp by eliminating the variable bb.
4
Solve for pp.
p=5p = 5
Dividing both sides of the equation by 77 gives the final number of premium mixture bags.

Anahtar Kavram

Solving systems of linear equations in context
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