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3 years ago

Solve the equations by substitution method: A) x+y=3, 2x+5y=12.

Mathematics

2 answers:

Wittaler [7]3 years ago

4 0

Answer:

x = 1, y = 2

Step-by-step explanation:

Original equations:

$x+y=3\\2x+5y=12$

Substitute y and solve for x:

$y=3-x\\2x+5y=12$

$2x+5(3-x)=12$

$2x+15-5x=12$

$-3x=-3$

$x=1$

Plug in x to solve for y:

$1+y=3$

$y=2$

x = 1, y = 2

Note: You can also substitute x and solve for y, then plug in y to solve for x. I did not do that here.

Margarita [4]3 years ago

4 0

Answer:

x+y=3

x=3-y equation 1

2x+5y=12

2(3-y)+5y=12

6-2y+5y=12

6+3y=12

3y=12-6

y=6÷3

y=2 equation 2

again ,

putting value of equation 2 in equation 1

x=3-y

x=3-2

x=1

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Step-by-step explanation:

Let x be the length and y be the width of the rectangular plot.

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x = 1500 - 2y ....(1)

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Put the value of x from equation (1) in (2)

$A=(1500-2y)y\\\\A=1500y-2y^2$ .....(3)

For largest area, differentiate above area equation wrt y.

$\dfrac{dA}{dy}=\dfrac{d}{dy}(1500y-2y^2)\\\\=1500-4y\\\\\text{Put}\ \dfrac{dA}{dy}=0\\\\1500-4y=0\\\\y=\dfrac{1500}{4}\\\\=375$

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3 years ago

The paper usage at a small copy center is normally distributed with a mean of 5 boxes of paper per week, and a standard deviatio

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Answer:

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Mean = demand for week = 5 boxes

We are required to find the safety stock to maintain at 99% service level.

At 99% level, the Z value is equal to 2.326.

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3 years ago

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Answer:

3.188

Step-by-step explanation:

Given that :

Sample data: 26.5, 28, 30.2, 29.6, 32.3, 24.7

Sample standard deviation (s) = 2.728

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Tstatistic formula :

(x - mu) / (s/sqrt(n))

n = sample size = 6 ; s = 2.728 ; mu = 25

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3 years ago

Solve the equations by substitution method: A) x+y=3, 2x+5y=12.​

Solve the equations by substitution method: A) x+y=3, 2x+5y=12.