Math Calculation Problems Help with it, calculation problems. Mathematical. The experts are here to

1.(-1/3) -(6) = 6-1 3 = 17 32(-3)-5/21 (-1/7) = -3+5 3=4 33

1/2 + (-2/3) + (1/4) + (1/3) = (-1/3) + (2/3) + (1/4) + 1/2 = -1 + 1 4=-3 4

4.1/3) and 2/3 = (2/3 + 1 and 1/3) = 2 + 4 = 6

1.(- a third) - (6).

Five and two-thirds.

2.(-3) -5/21 (-1/7).

One and a third.

3.1/2 + (-2/3) + (1/4) + (1/3) 3/4. 4.1/3) and 2/3

1.(-1/3) - (6) = 6 - 1 3 = 17 3

2.(-3) -5/21 (-1/7) = -3 + 5 3 = 4 3

3.1/2 + (-2/3) + (1/4) + (1/3) = (-1/3) + (2/3) + (1/4) + 1/2 = -1 + 1 4=-3 4

Because the denominator cannot be 0, x2-1≠0, i.e., x≠1 or -1; x+1≠0，x≠-1。

Let x=0 and the original formula is equal to -1

(+7/13) + (17) + (1 and 1/3) - (7) - (2 and 1/3) + (7/13).

I can't even read it, Xiaodi

(+7/13) + (17) + (1 and 1/3) - (7) - (2 and 1/3) + (7/13).

+7/13) + (7/13) + (1 and 1/3) - (2 and 1/3) + (17) - (7).

0 + (-1 and 1/3) + (2 and 1/3) + (17)-(7) = 1 + 10 = 11

+7/13) + (7/13) + (1 and 1/3) - (2 and 1/3) + (17) - (7).

In the first question, the number in the first bracket corresponds to the number in the second bracket and divides it, and the resulting three quotients can be multiplied by the brother; The second question is not easy to calculate; Question 3, no; Fourth, let 1998 be n and 1997 be m, and the formula is two mns multiplied by 10001 to get 0Question 5 Dayu, 1 divided by n (n + 1) is equal to 1 divided by n - 1 divided by (n + 1) to talk about imitation, so the result is. That's all for now, take a break, I'm exhausted.

The upper and lower bounds of the confidence interval are calculated as:

Bringing x means = 400, standard deviation s = 46, number of samples n = 400, and t = 2 into the formula, the confidence interval is [,

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