All categories

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

You might be interested in

Please help i cannot get it

Lerok [7]

Pi symbol raised to the 3 times x raised to the 4

7 0

3 years ago

Last year the robotics club had 30 members. This year the club has 24 members. Find the percent change in the number of members.

Naddika [18.5K]

Answer:

the answer is .6

Step-by-step explanation:

so 30 minus 24 is 6 turn 6 into percentage which is 0.6

4 0

3 years ago

Read 2 more answers

A rectangular plot of farmland will be bounded on one side by a river and on the other three sides by a single-strand electric f

likoan [24]

Step-by-step explanation:

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

The plot is bounded on one side by a river and on the other three sides by a single-strand electric fence. It means,

x+2y = 1500

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

We know that the area of a rectangular plot is given by :

A = xy ....(2)

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.

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

Put the value of y in equation (1).

x = 1500-2(375)

= 750 m

Put the value of y in equation (3).

$A =1500(375)-2(375)^2\\A=281250\ m^2$

Hence, the largest area is 281250 m² and its dimensions are 750 m and 375 m.

3 0

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

VladimirAG [237]

Answer:

1.649 approximately 2

Step-by-step explanation:

S.d = standard deviation = 0.5

Time taken = lead time = 2 weeks

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.

Therefore,

Safety stock = z × s.d × √Lt

= 2.326 × 0.5 x √2

= 1.649

Which is approximately 2.

7 0

3 years ago

Betty tabulated the miles-per-gallon values for her car as 26.5, 28, 30.2, 29.6, 32.3, and 24.7. The sample standard deviation i

Viefleur [7K]

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

Mean (mu) = 25

Tstatistic formula :

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

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

Sample mean (x) = (26.5 + 28 + 30.2 + 29.6 + 32.3 + 24.7) / 6

Sample mean (x) = 171.3 / 6 = 28.55

Tstatistic = (28.55 - 25) / (2.728 / sqrt(6))

Tstatistic = 3.55 / 1.1137013

Tstatistic = 3.1875692

3 0

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.