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Scorpion4ik [409]
3 years ago
7

Jennifer went to the post office for stamps. She bought the same number of 8-cent stamps and 10-cent stamps. She also bought as

many 2-cent stamps as both of the other two kinds combined. How many of each kind did she get if she paid a total of $4.40 for them all? Due today! IM SO CONFUSED
Mathematics
2 answers:
mamaluj [8]3 years ago
5 0
Write it out as a set of equation:
Let x be number of 8 cent stamps, y be 10 cent stamps, and z be 2 cent stamps.
x=y
z=x+y
8x+10y+2z=440
Lets first solve for x:
from x=y and z=2x(from first equation) the last equation is
8x+10x+4x=440
22x=440
x=20
know that x=20, you also know that y=20 as well, since z=x+y, z=40.
So 20 8-cent stamps, 20 10-cent stamps, and 40 2-cent stamps.
Ymorist [56]3 years ago
3 0
X=number of 8-cent stamp=number of 10-cent stamp
y=number of 2-cent stamp.
$4.40=400 cents

She bought the same number of 8.cent stamp and 10 -cent stamps, she also bought as many 2-cent stamps as both, therefore:
x+x=y  ⇒2x=y
We can suggest this system of equations:

2x=y
8x+10x+2y=440

We can solve this system of equation by substitution method.

8x+10x+2(2x)=440
8x+10x+4x=440
22x=440
x=440/22
x=20

y=2x
y=2(20)=40

Answer: She bought 20 stamps of 8 cents, 20 stamps of 10 cents, and 40 stamps of 2 cents
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Ksenya-84 [330]

                  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

\diamond\large\blue\textsf{\textbf{\underline{Given question:-}}}

       What is the equation of the line that passes through (-3, 6) and has a slope of -2?

\diamond\large\blue\textsf{\textbf{\underline{\underline{Answer and how to solve:-}}}}\diamond

     

First, we need to write the equation of the line in point-slope form:-

\sf{y-y_1=m(x-x_1)}

Replace y1 with 6, m with -2, and x1 with -3:-

\sf{y-6=-2(x-(-3)}

On simplification,

\sf{y-6=-2(x+3)}

On further simplification,

\sf{y-6=-2x-6}

Add 6 on both sides:-

\it{y=-2x}

<h3>Good luck with your studies.</h3>

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6 0
1 year ago
How do I find this, what’s the formula to find the 20th term and can anyone explain the formula? Will award brainliest
harina [27]

Answer:

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Step-by-step explanation:

The first differences of the sequence are ...

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  • 17-10 = 7
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Second differences are ...

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The second differences are constant, so the sequence can be described by a second-degree polynomial.

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Subtracting the first of these from half the second gives ...

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  a = 1 . . . . . simplify

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__

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<em>Comment on the solution</em>

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Margarita [4]

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4 0
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