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2 years ago

Solve the simultaneous equations 3x + y = 25 2x – y = 10

Mathematics

1 answer:

Darina [25.2K]2 years ago

4 0

Answer:

x=7 and y=4

Step-by-step explanation:

I will use the elimination method:

Since the co-efficient of both y's are the same number but different signs we add the 2 equations to eliminate the y:

3x + y =25
+ + +

2x - y = 10

Simplify:

5x=35

Divide both sides by 5:

5x÷5=35÷5

Simplify:

x=7

Substitute this into either equation 1 or 2 ( I chose 1):

3(7) + y = 25

21 + y = 25

Subtract 21 from both sides and simplify to get y:

21+y-21=25-21

y=4

Therefore x=7 and y=4

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Step-by-step explanation:

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3 years ago

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Answer:

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Step-by-step explanation:

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3 years ago

Read 2 more answers

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Answer:

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Step-by-step explanation:

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3 years ago

Mrs Hong had some milk. She used of it to bake some waffles and

Sergio [31]

Answer:

Mrs. Hong originally had 900 ml of milk

Explanation:

The complete question is in the attached image

Assume that the amount of milk Mrs. Hong originally had was x ml

We are given that:

1- She used $\frac{1}{6}$ of it to bake the waffles, therefore:

Amount used in baking waffles = $\frac{1}{6}x$ ml

2- She used 300 ml to bake a pie

3- Amount left is half the original amount, therefore:

Amount left = $\frac{1}{2}x$ ml

We know that:

Total amount = amount used in waffles + amount used in pie + amount left

Substitute with the givens and solve for x:

Total amount = amount used in waffles + amount used in pie + amount left

$x = \frac{1}{6}x + 300 + \frac{1}{2}x\\ \\x-\frac{1}{6}x-\frac{1}{2}x = 300\\ \\\frac{1}{3}x = 300\\ \\x = 300*3 = 900 ml$

This means that:

She originally had 900 ml of milk

Hope this helps :)

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3 years ago

A store pays $50 for a pair of shoes. The markup is 25%. a. What is the selling price for the shoes? b. What is the total cost f

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Answer:

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Step-by-step explanation:

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2 years ago