Answer: the cost of one cherry pie is $18 and the cost of one pumpkin pie is $20
Step-by-step explanation:
Let x represent the cost of one cherry pie.
Let y represent the cost of one pumpkin pie.
Lea sold 2 cherry pies and 4 pumpkin pies for a total of $116. This means that
2x + 4y = 116 - - - - - - - - - - - - - -1
Kali sold 7 cherry pies and 8 pumpkins pies for a total of $286. This means that
7x + 8y = 286 - - - - - - - - - - - - 2
Multiplying equation 1 by 7 and equation 2 by 2, it becomes
14x + 28y = 812
14x + 16y = 572
Subtracting, it becomes
12y = 240
y = 240/12 = 20
Substituting y = 20 into equation 1, it becomes
2x + 4 × 20 = 116
2x + 80 = 116
2x = 116 - 80 = 36
x = 36/2 = 18
The area of the surface is 144.708
The equation of the given surface is,
z=g(x,y)=xy
Solving the partial derivatives,
∂g∂x=y,∂g∂y=x
Substituting to the formula
S=∬√1+( ∂g∂x)2+(∂g∂y)2dA
Thus,
S=∬√1+(y)2+(x)2dAS=∬√1+x2+y2dA
The region in the XY-plane is defined by the intervals 0≤θ≤2π,0≤r≤4
Converting the integral into polar coordinates,
S=∫2π0∫40√1+r2rdrdθ
Integrating with respect to r
S=∫2π0[13(1+r2)32]40dθ
S=∫2π0(17√173−13)dθ
Integrating with respect to θ
S=(17√173−13)[θ]2π0
S≈144.708
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Answer:
1.27, -6.27 to the nearest hundredth,
or if you require it in exact form,
-2.5 + √14.25, -2.5 - √14.25.
Step-by-step explanation:
x^2 = -5x + 8
x^2 + 5x = 8
Competing the square:
(x + 2.5)^2 - 6.25 = 8
(x + 2.5) = 14.25
x + 2.5 = +/-√14.25
x = -2.5 + √14.25, -2.5 - √14.25
x = -2.5 + 3.77, -2.5 - 3.77
= 1.27, -6.27.
Answer:
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Step-by-step explanation:
