Use this data for question #14. The results for a survey of 120 students who were selected randomly are listed below:
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:
Step-by-step explanation:
To solve the equation, isolate x. Whatever you do to isolate x one on side, you must do to the other.
1) Multiply both sides by 9 to get rid of the fractions.
2) Distribute the 3 to 8x and 15. Then, combine like terms.
3) Move the 66 to the other side, subtracting 18 by 66, then divide each side by 20 to finally isolate x.
Thus, .
Answer:
Step-by-step explanation:
The area of a trapezium is given as;
Area = (a + b)h
where: a is the length of the upper side, b is the length of its base and h is its height.
This implies that; a = x - 4, b = x + 5, h = 2x and area = 351
Thus,
351 = ((x - 4) + (x + 50)) 2x
= (x - 4 + x + 5) x
531 = (2x + 1) x
= 2 + x
So that;
2 + x - 531 = 0
This gives a quadratic equation.