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raketka [301]
2 years ago
13

An alloy is composed of nickel, zinc, and copper in a 7:2:9 ratio. How many kilograms of each metal is needed to make 3.8 kg of

this alloy?
Mathematics
1 answer:
Tamiku [17]2 years ago
6 0
Ni : Zn: Cu = 7:2:9 =7x : 2x : 9x

7x+2x+9x = 3.8
18x=3.8
x=3.8/18=1.9/9≈0.21

Ni:   7x=7*0.21=1.47 ≈1.5 kg
Zn:  2x=2*0.21=0.42≈0.4 kg
Cu: 9x=9*0.21=1.89 ≈1.9 kg

Check 1.5+0.4+1.9 =3.8 True
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Answer:

4\sqrt{\pi}

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The circle area = the square area. Thus we have:

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Let L be the line with parametric equations x=2+t, y=1-t, z=1+3t.Let v=(1,2,0).Find vectors w1 and w2 such that v= w1 + w2, and
charle [14.2K]

Answer:

w1 = (-1/11, 1/11, -3/11)

w2 = (12/11, 21/11, 3/11)

Step-by-step explanation:

Direction ratio of w1 = Direction ratio of L (because parallel) = K+(1, -1, 3)

Let <a,b,c> be direction ratio of w2.

Then, <a,b,c>. <1,-1,3> = 0

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(1, 2, 0) = k(1, -1, 3) + (a, b, c)

a + k = 1

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c - 3k = 0

Solving 4 equations, a = 12/11, b= 21/11, c = 3/11, k=-1/11

So, w1 = -1/11(1, -1 ,3) = (-1/11, 1/11, -3/11)

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2 years ago
The number of newly reported crime cases in a county in New York State is shown in the accompanying table, where x represents th
Novay_Z [31]

Answer:

Step-by-step explanation:

I use  84+ CE

stat edit, then fill in the #s

then

vars 5

then

2'nd stat plot, on

then, click stat

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then click (4)(LinReg(ax+b))

then click enter 5 times

(y=-25.31428571x+1000.285714

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now, lets use computer:

y=-25.31(543)+1000.3

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this doesn't really work, so I will put 1999, 2000, 2001, 2002, 2003, 2004 instead of 0, 1, 2, 3, 4, 5 and do the same thing

now I get

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7 0
2 years ago
A store sells a certain tile for $2 per tile and a pint of paint for $3. A second store sells the same items for $1 per tile and
andreev551 [17]

Answer:

2 x plus 3 y equals 26. X plus 4 y equals 18

Step-by-step explanation:

Number of tiles, = x

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Store 2 :

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System of equation:

2x + 3y = 26 - - - (1)

x + 4y = 18 - - - - - (2)

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