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3 years ago

Help please! 99 Points!

2 answers:

7 0

Hey there,

As seeing the (mathematics's above) I would be more willing list the steps, but to just tell you the answer.

$\boxed{y = -2.56}$ and also $\boxed{y =1.88}$

Hope this helps.

~Jurgen

WITCHER [35]3 years ago

3 0

Combination method: add the two equations together

5)   <span>4x-9y=1 6) 3x - 2y = 14
+( - 4x+6y=-2 ) + (2x + 2y = 6)
---------------------- -------------------
0 - 5y = -1 5x + 0 = 20

-5y = -1 5x = 20

isolate the y isolate the x

-5y / -5 = -1/-5 5x/5 = 20/5

y = 1/5 x = 4

</span>4x-9y=1 3x - 2y = 14
4x - 9(1/5) = 1 3(4) - 2y = 14
4x - 9/5 = 1 12 - 2y = 14
4x - 9/5 (+9/5) = 1 (+9/5) 12 (-12) - 2y = 14 (-12)
4x = 14/5 -2y = 2
4x/4 = 14/5(/4) -2y(/-2) = 2(/-2)
x = 14/20 y = -1

Elimination method

7) 4x + 3y = 29 + (5x + 2y = 24)
eliminate one of the variables by multiply the number to both sides

2 (4x + 3y = 29) + 3 (5x + 2y = 24)

8x + 6y = 58
-( 15x + 6y = 72)
----------------------
-7x = - 14
-7x/-7 = -14/-7

x = 2

4(x) + 3y = 29
4(2) + 3y = 29
3y + 8 = 29
3y + 8 (-8) = 29 (-8)
3y = 21
3y/3 = 21/3

y = 7

8) like #7, you must   eliminate one of the variables by multiply the number to both sides

-4x - 2y = 14
-10x + 7y = -25

7(-4x - 2y = 14)
-2(-10x + 7y = -25)

-28x - 14y = 98
- (20x -14y = -25)
-----------------------
-48x = 123
-48x/-48 = 123/-48
x = -2.56

-4(-2.56) - 2y = 14
10.24 - 2y = 14
10.24(-10.24) - 2y = 14 (-10.24)
-2y = 3.76
-2y/-2 = 3.76/-2
y = -1.88

hope this helps

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Can someone help me with #1.

OLga [1]

Here slope is -2
and intercept is 4
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-2 x+4
if u have any doubt ask me
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8 0

2 years ago

When Mei does 17 push-ups and 6 sit-ups, it takes a total of 35 seconds. In comparison, she needs 41 seconds to do 20 push-ups a

Romashka [77]

Answer:

It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.

Step-by-step explanation:

Given:

Let the time taken for push-ups be 'x'.

Let the time taken for sit-ups be 'y'.

Now Given:

17 push-ups and 6 sit-ups, it takes a total of 35 seconds.

So we can say that;

$17x+6y=35 \ \ \ \ equation \ 1$

Also Given:

41 seconds to do 20 push-ups and 7 sit-ups.

so we can say that;

$20x+7y=41 \ \ \ \ equation \ 2$

Now Multiplying equation 1 by 7 we get;

$7(17x+6y)=35\times7\\\\119x+42y= 245 \ \ \ \ equation \ 3$

Now Multiplying equation 2 by 6 we get;

$6(20x+7y)=41\times6\\\\120x+42y = 246 \ \ \ \ equation\ 4$

Now Subtracting equation 3 from equation 4 we get;

$120x+42y-(119x+42y)=246-245\\\\120x+42y-119x-42y=1\\\\x=1\ sec$

Now substituting the value of x in equation 1 we get;

$17x+6y=35\\\\17\times1+6y=35\\\\17+6y=35\\\\6y=35-17\\\\6y= 18\\\\y=\frac{18}6 = 3\ seconds$

Hence It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.

7 0

2 years ago

Help!!!!! Solve the distance??

hram777 [196]

Answer:

531.4

Step-by-step explanation:

ED/AE=BC/AB

ED=AE*BC/AB

ED=240*620/280

ED=531.4

6 0

2 years ago

Explain how you know 21/100 is greater than 1/5

Nataly_w [17]

This problem can be solved using equivalent fractions. The first step in resolving this problem is to realize that fractions are best compared when they both have the same denominator. In this case, I will choose to make that common denominator 100. There is no need to rewrite the fraction $\frac{21}{100}$ as the denominator for this fraction is already 100. The fraction $\frac{1}{5} =\frac{20}{100}$ . This is achieved by multiplying both the numerator and denominator by 20. Now that the two fractions have the same denominator, we can easily see that $\frac{21}{100}$ is greater than $\frac{1}{5}$ because it is greater than its equivalent fraction.