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nignag [31]
2 years ago
11

Substitution method for 7x + 21y =42​

Mathematics
1 answer:
ira [324]2 years ago
4 0

Answer:

(6,2)

Step-by-step explanation:

Use desmos

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How many gallons of a 50% antifreeze solution must be mixed with 60 gallons of 30% antifreeze to get a mixture that is 40% antif
Mariulka [41]

I don't know what the "six-step method" is supposed to be, so I'll just demonstrate the typical method for this problem.

Let <em>x</em> be the amount (in gal) of the 50% antifreeze solution that is required. The new solution will then have a total volume of (<em>x</em> + 60) gal.

Each gal of the 50% solution used contributes 0.5 gal of antifreeze. Similarly, each gal of the 30% solution contributes 0.3 gal of antifreeze. So the new solution will contain (0.5 <em>x</em> + 0.3 * 60) gal = (0.5 <em>x</em> + 18) gal of antifreeze.

We want the concentration of antifreeze to be 40% in the new solution, so we need to have

(0.5 <em>x</em> + 18) / (<em>x</em> + 60) = 0.4

Solve for <em>x</em> :

0.5 <em>x</em> + 18 = 0.4 (<em>x</em> + 60)

0.5 <em>x</em> + 18 = 0.4 <em>x</em> + 24

0.5 <em>x</em> - 0.4 <em>x</em> = 24 - 18

0.1 <em>x</em> = 6

<em>x</em> = 6/0.1 = 60 gal

6 0
3 years ago
Cole brought chocolate and vanilla cupcakes to school for his birthday. 40 students decided to take a cupcake, and 90% of them p
nikdorinn [45]

Answer:

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Step-by-step explanation:

40 * 90%

= 40 * 0.9

= 36

6 0
3 years ago
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What can i add to 1,663,134 to make 2,148,431​
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Answer:

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Step-by-step explanation:

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egoroff_w [7]

Steps to solve:

151 - 4(32 - 2)

~Distribute

151 - 128 - 8

~Subtract

23 - 8

15

Best of Luck!

3 0
3 years ago
Rule: y is 1/3 times as large as x. If x=0 y=? x=6 y=? x=12 y=?
elixir [45]

Answer: can you put a picture

Step-by-step explanation:

6 0
2 years ago
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