Solve this system of equations by using the elimination method. 2x - 2y = 2. 5x + 2y = 12 (2, [?])
1 answer:
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Answer:
- cookie: $1.25
- cupcake: $2.75
Step-by-step explanation:
Let x and y represent the cost of a cookie and a cupcake, respectively.
4x +3y = 13.25
5x +2y = 11.75 . . . . . . the system of equations
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By Cramer's rule:
x = (3(11.75) -2(13.25))/(3(5) -2(4)) = 8.75/7 = 1.25
y = (13.25(5) -11.75(4))/7 = 19.25/7 = 2.75
The cost of one cookie is $1.25; the cost of one cupcake is $2.75.
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Cramer's rule gives the solution to the system of equations ...
ax +by =c
dx +ey = f
as ...
∆ = bd -ea
x = (bf -ec)/∆
y = (cd -fa)/∆
Answer:
Option C
Step-by-step explanation:
we have
step 1
Group terms that contain the same variable, and move the constant to the opposite side of the equation
step 2
Factor -6 leading coefficient'
step 3
Complete the square
Remember to balance the equation by adding the same constants to each side
step 4
Rewrite as perfect squares
simplify