Answer:
No mistake
Step-by-step explanation:
2x + y = 5
x - 2y = 10
y = 5 - 2x
x - 2(5 - 2x) = 10
x - 10 + 4x = 10
5x - 10 = 10
5x = 20
x = 4
2(4) + y = 5
y = -3
She made no mistake
You can check by plugging in x = 4 and y = -3 into the original equations . They fit exactly.
For this case we have the following equation:

Where,
w: The weight of a spring in pounds
E: the energy stored by the spring in joules.
Substituting values we have:

Making the corresponding calculation:
Answer:
the approximate weight of the spring in pounds is:
Answer: 128.5km
Step-by-step explanation:
Since we are given the information that the distance by road from town A to town B is 257 km. To get 50% of the distance, we simply have to multiply the distance given by 50%. This will be:
= 50% × 257km
= 50/100 × 257km
= 0.5 × 257km
= 128.5km
Therefore, 50% of the distance is 128.5km.

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Explanation:</h2><h2>
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In this problem we have the following data:

Speed, time and distance are related with the following formula:

<h2>Learn more:</h2>
Speed: brainly.com/question/14095729
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Answer:
9
Step-by-step explanation:
9.
y coordinate gives the vertical distance