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4 years ago

What is the answer for this question using the elimination formula

Mathematics

2 answers:

nalin [4]4 years ago

7 0

It is convenient to add 3 times the first equation to the second. This will eliminate x.

In general, you want to find some multiple of one equation that you can combine with some multiple of the other to cause one of the variable coefficients to become zero. Here, we see that x is by itself in one equation, so it is convenient to multiply that by a suitable factor to cancel the x-term in the other equation. The x-coefficient in the second equation is -3, so when we multiply the first equation by +3 and add the result to the second equation, we get +3x-3x = 0x in the result.

3(x +5y) +(3y -3x) = 3(17) + (21)

... 18y = 72 . . . . . . collect terms

... y = 4 . . . . . . . . . divide by 18

Substitute into the first equation:

... x + 5·4 = 17

... x = -3 . . . . . . . . subtract 20

The solution is (x, y) = (-3, 4).

_____

Here, we note the second equation has terms that all have a factor of 3 that can be removed. That is, the second equation can be rewritten as

... y - x = 7

Now, we can add this directly to the first equation to eliminate the x terms.

... (y -x) +(x +5y) = 7 + 17

... 6y = 24 . . simplify

... y = 4 . . . . same as above

We could also subtract 5 times the new second equation from the first to eliminate y.

... (x +5y) -5(y -x) = (17) -5(7)

... 6x = -18 . . . . . . simplify

.... x = -3 . . . . . . . . divide by the coefficient of x

amid [387]4 years ago

7 0

Thats your answers... hope it can help... :)

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If sine theta equals three over four, what are the values of cos θ and tan θ?

ankoles [38]

Answer:

Part 1) $cos(\theta)=(+/-)\frac{\sqrt{7}}{4}$

cosine theta equals plus or minus square root of seven over 4

Part 2) $tan(\theta)=(+/-)\frac{3}{\sqrt{7}}$

tangent theta equals plus or minus three over square root of seven

$tan(\theta)=(+/-)3\frac{\sqrt{7}}{7}$

tangent theta equals plus or minus three times square root of seven over seven

Step-by-step explanation:

we have that

The sine of angle theta is equal to

$sin(\theta)=\frac{3}{4}$

Is positive

therefore

The angle theta lie on the I Quadrant or in the II Quadrant

Part 1) Find the value of the cosine of angle theta

Remember that

$sin^{2} (\theta)+cos^{2} (\theta)=1$

we have

$sin(\theta)=\frac{3}{4}$

substitute and solve for cosine of angle theta

$(\frac{3}{4})^{2}+cos^{2} (\theta)=1$

$cos^{2} (\theta)=1-(\frac{3}{4})^{2}$

$cos^{2} (\theta)=1-\frac{9}{16}$

$cos^{2} (\theta)=\frac{7}{16}$

$cos(\theta)=(+/-)\frac{\sqrt{7}}{4}$

cosine theta equals plus or minus square root of seven over 4

Part 2) Find the value of tangent of angle theta

we know that

$tan(\theta)=\frac{sin(\theta)}{cos(\theta)}$

we have

$sin(\theta)=\frac{3}{4}$

$cos(\theta)=(+/-)\frac{\sqrt{7}}{4}$

substitute

$tan(\theta)=\frac{\frac{3}{4}}{(+/-)\frac{\sqrt{7}}{4}}$

$tan(\theta)=(+/-)\frac{3}{\sqrt{7}}$

tangent theta equals plus or minus three over square root of seven

Simplify

$tan(\theta)=(+/-)3\frac{\sqrt{7}}{7}$

tangent theta equals plus or minus three times square root of seven over seven

4 0

3 years ago

Nevaeh conducted a scientific experiment. For a certain time, the temperature of a compound rose 2 1/4 degrees every 1 4/5 hours

Effectus [21]

Answer:

To find the amount the temp rose in one hour, you divide 24 by 14.

24. 5. 12

—- ~1.7, or 1—, or —-

14. 7. 7

I hope this helped ^.^

Have a good day mate^.^

May i also have brainliest? <3

7 0

2 years ago

Read 2 more answers

John batted 9 times for an average of 32. What was his total?

krek1111 [17]

Answer:

288

Step-by-step explanation:

From a data set, the average would be the "central" value of that set. It has the formula:

$Average = \frac{Sum}{Number}$

Where

Sum means the sum of all the numbers

Number means the Number of Numbers there are in total

Here, It is given:

Average = 32

Number = 9

So we substitute and find the "sum" to be:

$Average = \frac{Sum}{Number}\\32 = \frac{Sum}{9}\\Sum=32*9\\Sum=288$

The total (sum) is 288

3 0

3 years ago

Jane has 63m ribbon.If she cuts 56m 21cm ribbon from it,what length of ribbon will be left.

marta [7]

Exchange : 63m = 6300 cm; 56m21cm= 5621cm
So the lengths of the ribbon will be left is : 6300 - 5621 = 679cm = 6.79 m

Hope it helps! If it is, Brainliest please!

7 0

3 years ago

HELP!!!

MatroZZZ [7]

Answer:

B. Length A of Rasheeda’s garden is 27 ft.

C. Length B of the book’s garden is 12 ft.

E. Length A of the book’s garden is 9 ft longer than length A of Rasheeda’s garden.

Step-by-step explanation:

step 1

Find the dimension of the book's garden

we know that

Book scale: 1 inch = 2 feet

That means

1 inch in the drawing represent 2 feet in the actual

To find out the actual dimensions, multiply the dimension in the drawing by 2

Length A of the book’s garden

$18\ in=18(2)=36\ ft$

Width B of the book’s garden

$6\ in=6(2)=12\ ft$

step 2

Find the dimension of Rasheeda’s garden

we know that

Rasheeda's Scale: 2 inch = 3 feet

That means

2 inch inches the drawing represent 3 feet in the actual

To find out the actual dimensions, multiply the dimension in the drawing by 3 and divided by 2

Length A of Rasheeda's garden

$18\ in=18(3/2)=27\ ft$

Width B of Rasheeda's garden

$6\ in=6(3/2)=9\ ft$

Verify each statement

A. Length A of the book’s garden is 18 ft.

The statement is false

Because, Length A of the book’s garden is 36 ft (see the explanation)

B. Length A of Rasheeda’s garden is 27 ft.

The statement is true (see the explanation)

C. Length B of the book’s garden is 12 ft

The statement is true (see the explanation)

D. Length B of Rasheeda’s garden is 6 ft.

The statement is false

Because, Length B of Rasheeda’s garden is 9 ft. (see the explanation)

E. Length A of the book’s garden is 9 ft longer than length A of Rasheeda’s garden.

The statement is true

Because the difference between 36 ft and 27 ft is equal to 9 ft

F. Length B of the book’s garden is 3 ft shorter than length B of Rasheeda’s garden.

The statement is false

Because, Length B of the book’s garden is 3 ft greater than length B of Rasheeda’s garden.

4 0

3 years ago

Read 2 more answers