888… 88 (100 in total) times 666 What is the remainder of the product of 66 divided by 7?

888… 88 (100 in total) times 666 What is the remainder of the product of 66 divided by 7?

one hundred and eleven thousand one hundred and eleven
Six ones, divisible by seven
So 888888666666 can be divided by 7
100 △ 6 = 16 more than 4
888... 888 * 666... 666 (100 for 8 and 6)
The remainder of 7,
It's 8888 * 6666 divided by 7
8888*6666=59247408
59247408 △ 7 = 8463915 more than 3
So the remainder is 3

There are four numbers 3, - 5,7,13. How to calculate them to make the result equal to 24
Addition, subtraction, multiplication and division, brackets are OK
help!
Each number can only be used once

I can't figure it out

Find the general solution of the differential equation y '' 4Y '4Y = Xe ^ X
It's y '' + 4Y '+ 4Y = Xe ^ X

A:
y''+4y'+4y=xe^x
Characteristic equation a ^ 2 + 4A + 4 = 0
The solution is a = - 2
The general solution of homogeneous equation is y = (C1 + c2x) e ^ (- 2x)
Let the special solution be y * = (AX + b) e ^ X
y*'=ae^x+(ax+b)e^x=(ax+a+b)e^x
y*''=(ax+2a+b)e^x
Substituting into the original equation is as follows:
(ax+2a+b)e^x+4(ax+a+b)e^x+4(ax+b)e^x=xe^x
So:
9ax+6a+9b=x
So:
9a=1
6a+9b=0
The solution is: a = 1 / 9, B = - 2 / 27
So: y * = (1 / 27) * (3x-2) e ^ x
So: the general solution is y = (C1 + c2x) e ^ (- 2x) + (1 / 27) * (3x-2) e ^ X

It is known that there are only six integer solutions to the inequality system X − a ＞ 03 − 2x ＞ 0, then the value range of a is ()
A. （-∞，-4）B. [-5，-4）C. （-5，+∞）D. (−5，−32)

From the system of inequalities x − a ＞ 03 − 2x ＞ 0, we can get a ＜ x ＜ 32. From the meaning of the title, we can get that the interval (a, 32) contains six integers: - 4, - 3, - 2, - 1, 0, 1,... - 5 ≤ a ＜ - 4, so we choose: B

Use vertical formula to calculate. 25800 △ 700 (expressed by circular decimal) & nbsp; & nbsp; & nbsp; & nbsp; 2.34 × 0.47 (accurate to the hundredth)

25800÷700=36.•85714•2；2.34×0.47≈1.10；

Find the limit (see the figure below) Lim [(A1 ^ x + A2 ^ x +...) +An ^ x) / N] ^ (1 / x) where a1, A2 , an is a positive number

When seeking the limit, the first step is to use the law of lobida

7X+3=4X+8

7X+3=4X+8
7X-4X=8-3
3X=5
X=5/3

1. A barrel of oil weighs 20 kg. After 1 / 3 of the oil is poured out, the barrel weighs 14 kg. How many kg
2. The sum of a and B is 312, 1 / 2 of a is 18 more than B. what is the number of a and B?
3. Salt accounts for 1 / 21105 kg of salt water. How many grams of salt are there in salt water?

20-14 = 6 (one third of the weight of oil)
6 * 3 = 18 (weight of oil)
20-18=2
Answer It weighs two kilos
Let a = x, B = y
X+Y=318
1/2X-18=Y
We get x = 220, y = 92

Determine the continuity and differentiability of function, f (x) = SiNx, x0, x = 0. The second formula is the third power of e minus 1
Options: (a) continuous and differentiable when x = 0 (b) continuous and non differentiable when x + 0 (c) discontinuous point is 0 (d) differentiable but discontinuous when x = 0

A

How to solve 4x: 15 = 14: 56?

4x：15=14：56
4x：15=1：4
16x=15
x=15/16