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ahrayia [7]
3 years ago
5

How do I solve this system using substitution: y = x + 4; y = 3x

Mathematics
2 answers:
Kisachek [45]3 years ago
8 0
Y = x + 4
y = 3x

 3x = x + 4
<u>- x  - x        </u>
 <u>2x</u> = <u>4</u>
  2     2
   x = 2
y = x + 4
y = 2 + 4
y = 6
(x, y) = (2, 6)
Olin [163]3 years ago
4 0
You just do 
3x=x+4
subtract x from both sides
2x=4
divide 2 from both sides
x=2
y=2+4
y=6
(x,y)= (2,6)
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If B is the midpoint of line AC, AC = CD, AB = 3x+4, AC=11x-17, and CE = 49, find DE. (Show work)
larisa [96]

Answer:

2(3x+4) = 11x-17

6x+8 = 11x-17

25=-5x

x=-5

11x-17

55-17

38

AC = 38

CD = 38

49-38 = 11

DE = 11

Let me know if this helps!

3 0
2 years ago
Find the slope of the line going through the points (11,5) and (20,5)
Pani-rosa [81]
So remember the formula for working out the slope:

(y2 - y1) ÷ (x2 - x1)

We already know two points:

(11, 5) and (20, 5) (Remember points are like (x, y)


Therefore y2 = 5 and y1 = 5 and x2 = 20 and x1 = 11

Substitute these into the formula from the start:

(y2 - y1) ÷ (x2 - x1)
(5 - 5) ÷ (20 - 11)
0 ÷ 9

And we can determine the slope is equal to 0 as 0 ÷ 9 = 0
4 0
2 years ago
Zahra compares two wireless data plans. Which equation gives the correct value of n, the number of GB, for which Plans A and B c
Elden [556K]

The equation which gives the correct value of n, the number of GB, for which Plans A and B cost the same is 8n = 20 + 6(n-2)

To determine which equation gives the correct value of n, the number of GB, for which Plans A and B cost the same, we will first solve the equations.

  • For the first equation

8n = 20 + 6n

Collect like terms

8n - 6n = 20

2n = 20

Then, n = 20 ÷ 2

n = 10 GB

For Plan A

No initial fee and $8 for each GB

Here, 10GB will cost 10 × $8 = $80

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 10GB will cost $20 + (8 × $6) = $20 + $48 = $68

∴ Plans A and B do not cost the same here.

  • For the second equation

8n = 20(2n) + 6

First, clear the bracket

8n = 40n + 6

Now, collect like terms

40n - 8n = 6

42n = 6

∴ n = 6 ÷ 42

n = 1/7 GB

For Plan A

No initial fee and $8 for each GB

Here, 1/7GB will cost 1/7 × $8 = $1.14

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 1/7GB will cost $20 (Since the lowest cost is $20)

∴ Plans A and B do not cost the same here.

  • For the third equation

8n = 20 + 6(n-2)

First, clear the brackets

8n = 20 + 6n - 12

Now, collect like terms

8n - 6n = 20 - 12

2n = 8

n = 8 ÷ 2

n = 4 GB

For Plan A

No initial fee and $8 for each GB

Here, 4GB will cost 4× $8 = $32

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 4GB will cost $20 + (2 × $6) = $20 + $12 = $32

Plans A and B do not cost the same here.

∴ Plans A and B do cost the same here

  • For the fourth equation

8n = 20 + 2n + 6

Collect like terms

8n - 2n = 20 + 6

6n = 26

n = \frac{26}{6}

n = \frac{13}{3} GB or 4\frac{1}{3} GB

For Plan A

No initial fee and $8 for each GB

Here, \frac{13}{3} GB will cost \frac{13}{3}  × $8 = $34.67

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 4\frac{1}{3}GB will cost $20 + ( 2\frac{1}{3}× $6) = $20 + $14 = $34

∴ Plans A and B do not cost the same here.

Hence, the equation which gives the correct value of n, the number of GB, for which Plans A and B cost the same is 8n = 20 + 6(n-2)

Learn more here: brainly.com/question/9371507

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How do you work out pie charts if thewy don't have any numbers on them?
abruzzese [7]
Adding on to the previous, estimate FRACTIONS of the chart, and then figure out the percentage of those fractions
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3 years ago
What percent of 128 is 66
gavmur [86]
66/128 * 100
51.56 % if rounding to the nearest hundredth.
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52 % if rounding to the nearest whole number.
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3 years ago
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