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Zorluk: OrtaSystems of Linear Equations

A bakery sells blueberry muffins and bran muffins. The total cost of 66 blueberry muffins and 44 bran muffins is $22.00\$22.00. The total cost of 55 blueberry muffins and 88 bran muffins is $26.50\$26.50. What is the cost, in dollars, of 11 blueberry muffin?

Cevap: 2.5 dollars

Cevap

The cost of one blueberry muffin is 2.5 dollars.
The correct answer is 2.5. By setting up the system of linear equations 6x+4y=226x + 4y = 22 and 5x+8y=26.55x + 8y = 26.5, where xx represents the cost of one blueberry muffin and yy represents the cost of one bran muffin, we can solve for xx. Multiplying the first equation by 2 gives 12x+8y=4412x + 8y = 44. Subtracting the second equation, 5x+8y=26.55x + 8y = 26.5, from the modified first equation yields 7x=17.57x = 17.5. Dividing by 7 results in x=2.5x = 2.5.

Adım Adım Çözüm

1
Set up a system of equations.
6x+4y=226x + 4y = 22 and 5x+8y=26.55x + 8y = 26.5
Translate the context into mathematical statements where xx is the price of a blueberry muffin and yy is the price of a bran muffin.
2
Multiply the first equation by 2.
12x+8y=4412x + 8y = 44
Align the coefficients of yy to facilitate elimination.
3
Subtract the second equation from the modified first equation.
7x=17.57x = 17.5
Eliminate the variable yy to solve for xx.
4
Divide by 7.
x=2.5x = 2.5
Isolate the variable xx to find the cost of a blueberry muffin.

Anahtar Kavram

Solving systems of two linear equations using elimination.

Alternatif Yöntem

Alternatively, solve for yy in terms of xx using the first equation: y=5.51.5xy = 5.5 - 1.5x. Substitute this expression into the second equation: 5x+8(5.51.5x)=26.55x + 8(5.5 - 1.5x) = 26.5, which simplifies to 5x+4412x=26.5Rightarrow7x=17.5Rightarrowx=2.55x + 44 - 12x = 26.5 \\Rightarrow -7x = -17.5 \\Rightarrow x = 2.5.
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