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3 years ago

X+y=525 3x+7y=2775 A.340 B.280 C.225 D.300

Mathematics

1 answer:

Nitella [24]3 years ago

4 0

Answer: C.225

Step-by-step explanation: for this case we need to calculate the value of x, to complete this we have 2 equations,

you can stat with simple equation X+y=525, if you clear x we get the following equation.

x = 525 - y

after that we are going to replace x in the major equation.

3x + 7y = 2775

After replace x we get the following equation

3 * (525 - y) + 7y = 2775

after that, the 3 is going to multiply each value into the parenthesis

3 * 525 - 3 * + 7y = 2775

after resolve the product we get the following equation

1575 - 3y + 7y = 2775

you need resolve the equation with values which has the y

getting the following result

1575 + 4y = 2775

after that you pass the 1575 to the other side with the sign of subtraction

4y = 2775 - 1575

4y = 1200

after that, the 4 which is multiplying pass to the other side dividing

then

y = 1200/4

y = 300

finally, you will replace the value of y in the equation where we clear x, this equation.

x = 525 - y

if you replace y

x = 525 - 300

x = 225

then value of the x is 225

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it took him 10 mintues to run 5 laps

Step-by-step explanation:

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3 years ago

Gcf of 12x^5y and #2x^6y

Murrr4er [49]

Greatest common factor is 1 for the first one and the second one is also 1

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3 years ago

Find the sum of the geometric sequence. three divided by two, three divided by eight, three divided by thirty two, three divided

Lynna [10]

Answer: we have that

[3/2,3/8,3/32,3/128,3/512]

the sum of the geometric sequence is [3/2+3/8+3/32+3/128+3/512]

=(1/512)*[256*3+64*3+16*3+4*3]

=(3/512)*[256+64+16+4]

=(3/512)*[340]

=(1020/512)

=255/128---------> 1.9922

the answer is

1.9922

another way to calculate it

is through the following formula

∑=ao*[(1-r^n)/(1-r)]

where

ao---------> is the first term

r----------> is the common ratio between terms

n----------> is the number of terms

ao=1.5

r=1/4-----> 0.25

n=5

∑=1.5*[(1-0.25^5)/(1-0.25)]-------------> 1.99

Step-by-step explanation: we have that

[3/2,3/8,3/32,3/128,3/512]

the sum of the geometric sequence is [3/2+3/8+3/32+3/128+3/512]

=(1/512)*[256*3+64*3+16*3+4*3]

=(3/512)*[256+64+16+4]

=(3/512)*[340]

=(1020/512)

=255/128---------> 1.9922

the answer is

1.9922

another way to calculate it

is through the following formula

∑=ao*[(1-r^n)/(1-r)]

where

ao---------> is the first term

r----------> is the common ratio between terms

n----------> is the number of terms

ao=1.5

r=1/4-----> 0.25

n=5

∑=1.5*[(1-0.25^5)/(1-0.25)]-------------> 1.99

8 0

3 years ago

Plsss help. Thanks!!

slava [35]

Answer:

401

Step-by-step explanation:

1. Approach

To solve this problem, one first has to think about the given figure in a certain way. In the figure, one can see that it is a circle attached on either side of a rectangle. To find the perimeter of the figure, one has to find the circumference of the circle and then add two sides of the rectangle to the answer

2. Circumference of the circle

The formula to find the circumference of a circle is;

$2r$ (pi) or $d$ (pi)

~ diameter times the value (pi)

Normally to find the circumference of a semicircle, one would have to divide this formula by 2, but since in this case, one has to add two congruent semicircles, so therefore, the effect of dividing the equation by two, only to multiply by two again cancels, and hence, there is no need to divide by 2.

Substitute in the values;

(78)(pi)

~ 245

3. Find the perimeter of the entire object

Now, one has to add the two additional sides of the figure, to the circumferences of the semicircles to get the final answer;

78 + 78 + 245

= 401

3 0

2 years ago

Read 2 more answers

the numbers of girls in the choir is 4 times the number of boys in the choir .the total number of students is 60..how many girls

Inessa05 [86]

First, make up some variables to represent the number of Girls and Boys in the choir.

B = number of boys
G = number of girls

You know that there are 4 times as many girls in the choir as boys. Therefore, the equation you can write is:
$\frac{B}{G} = \frac{1}{4}$

If you cross-multiply, then you get the simplified equation:
G = 4B

Intuitively this makes sense since if you multiplied the number of boys in the class by 4, that would be equal to the number of girls you have.

Now, we know that the total class size is 60. So girls plus boys equals 60:
G+B = 60

To solve the equation, replace the G in this equation with the replacement you found before, 4B.
G + B = 60 -->
4B + B = 60 -->
5B = 60 -->
B = 12

However, you are trying to find the number of girls, so plug the answer back into your equation.
G + B = 60 -->
G + 12 = 60 -->
G + 12 -12 = 60 - 12 -->
G = 48

The number of girls you have is 48.

6 0

3 years ago