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tester [92]
3 years ago
4

Petra records the score in each test she takes.

Mathematics
1 answer:
Ahat [919]3 years ago
4 0

Answer:

x-n+1

Step-by-step explanation:

Given the mean of n terms as x, and of n-1 as x+1:

We know that  \bar X=\frac{1}{n}\sum x_i for n terms.

Therefore \sum x_n=n \bar X for n terms;

For n-1  terms; \sum x_n_-_1=(n-1)(x+1)=nx-x+n-1

To find the nth score, we subtract the sum of (n-1) terms from the sum of n terms:

n^t^h term=

nx-(nx-x+n-1)\\=x-n+1

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Will give brainliest to correct answer
yanalaym [24]

Answer:

A or B or C or D, one of those

5 0
3 years ago
What is the solution to {y>2x+5 (over) y<-3x+5
Alecsey [184]

Look at the picture.



\left\{\begin{array}{ccc}y > 2x+5\\y < -3x+5\end{array}\right\\\\y=2x+5\\for\ x=-2\to y=(2)(-2)+5=-4+5=1\to(-2;\ 1)\\for\ x=0\to y=(2)(0)+5=0+5=5\to(0;\ 5)\\\\y=-3x+5\\for\ x=0\to y=(-3)(0)+5=0+5=5\to(0;\ 5)\\for\ x=2\to y=(-3)(2)+5=-6+5=-1\to(2;\ -1)

8 0
3 years ago
Which quadratic equation has roots - 2 and 1/5 :
Sladkaya [172]

Answer:

5 {x}^{2}  \:  +  \: 8x \:  - 2 \:  =  \: 0

Step-by-step explanation:

sum \: of roots =  - 2 +  \frac{1}{5}  = - \frac{8}{5}  \\ product \: of \: roots =  - 2 \times  \frac{1}{5}  =  -  \frac{2}{5}  \\ from \: general \: equation \\ a {x}^{2}  + bx + c = 0 \\  {x}^{2}  +  \frac{8}{5} x  \: -   \frac{2}{5}  = 0 \\ 5 {x}^{2}   \:  +  \: 8x \:  - 2 \:  =  \: 0

7 0
3 years ago
Describe the solution to the inequality c is lesser than or equal to -2
nadya68 [22]

Answer: The solution would be any value that is -2 and lower.


Step-by-step explanation:

Okay, so our equation is c ≤ -2, so any value that is -2 and below would be correct for this inequality.

4 0
3 years ago
What is the solution set for 9x2-25=0
Alexandra [31]

Answer: i hope i helped if not im truly sorry

Solving for 9x^2 - 25 = 0

Standard form:

9x2 − 25 = 0

Solutions based on quadratic formula:

x1  

= −0 − √ 02 − 4×9×(−25)  

2×9

= 0 − 30 × √ 1  

18

≈ −1.667

x2  

= −0 + √ 02 − 4×9×(−25)  

2×9

= 0 + 30 × √ 1  

18

≈ 1.667

Extrema:

Min = (0, −25)

Step-by-step explanation: im not dumb and im not smart

4 0
3 years ago
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