Answer:
1.) 9
2.) 20
Step-by-step explanation:
1.) 39 is incorrect because they didn't follow the PEMDAS rule.
They subtracted 2 from 15 which is 13, and then they multiplied 13 by 3.
<u>The correct way is to multiply 2 times 3 which is 6, and then subtract 6 from 15 which is 9.</u>
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2.) 12 is incorrect because they didn't use PEMDAS.
They added 8 to 16 which is 24, and then divided 24 by 2.
<u>The correct way is to divide 8 by 2 which is 4, and then add for to 16 which 20.</u>
The mathematical expression for the given statement is 50 + 10x
<h3>How to write a mathematical expression for this statement?</h3>
The given parameters are:
Initial distance = 50 laps
Rate of increment = 10 laps each week
Represent the number of weeks with x
So, we have:
Number of laps = Initial distance + Rate of increment * Number of weeks
This gives
Number of laps = 50 + 10 * x
Evaluate
Number of laps = 50 + 10x
Hence, the mathematical expression for the given statement is 50 + 10x
Read more about expressions at:
brainly.com/question/723406
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Answer:
Step-by-step explanation:
![(x+1-i)(x+1+i)\\\\=(x+1)^2 -i^2~~~~~~~~~~~~~;[a^2 -b^2 = (a+b)(a-b)]\\\\=x^2 +2x +1 -(-1)\\\\=x^2 +2x +1+1\\\\=x^2 +2x +2](https://tex.z-dn.net/?f=%28x%2B1-i%29%28x%2B1%2Bi%29%5C%5C%5C%5C%3D%28x%2B1%29%5E2%20-i%5E2~~~~~~~~~~~~~%3B%5Ba%5E2%20-b%5E2%20%3D%20%28a%2Bb%29%28a-b%29%5D%5C%5C%5C%5C%3Dx%5E2%20%2B2x%20%2B1%20-%28-1%29%5C%5C%5C%5C%3Dx%5E2%20%2B2x%20%2B1%2B1%5C%5C%5C%5C%3Dx%5E2%20%2B2x%20%2B2)
I think it’s the third one and the last two. I’m sorry if it’s wrong
