Practical problems of linear equation with one variable (2317:31:0) There are five Sundays in a month. The sum of the five Sundays is 75. What's the last Sunday of the month?

Let the first Sunday be the X
X + (x + 7) + (x + 14) + (x + 21) + (x + 28) = 75, x = 1, x + 28 = 29
The last Sunday of the month is the 29th

Party A, Party B and Party C jointly contribute to the establishment of a company. The investment amount of Party A is 40% of the total investment amount. The investment amount of Party B is 200000 yuan more than one third of the total investment amount, and the investment amount of Party C is 80000 yuan less than half of the total investment amount of Party A. how much is the total investment amount of the company?

Suppose the total investment is x, then a invests 40% x, B invests (13X + 20), C invests X - [40% x + (13X + 20)]. According to the title, we get X - [40% x + (13X + 20)] = 12 × 40% X-8, and the solution is x = 180. A: the total investment of this company is 1.8 million yuan

Please give a detailed answer to the math summer homework of grade one, thank you! (9 15:53:56)
Given x + y = A & # 160; - # 160; - # 160; xy = B & # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; - # 160; then the square of X (y) + the square of Y (x)=

xy²+x²y=xy(x+y)=ab

Idiotic questions... Scientific counting (9 22:56:18)
33500 billion, how to express it by scientific counting?
It's the scientific counting method in mathematics

By the way, I would like to ask how to convert the scientific counting method to the general number

33500 billion = 335000 * 10 ^ 8 = 3.35 * 10 ^ 13

Ding Ding read a story book. On the first day, he read a quarter of it. On the second day, he read 60 pages. At this time, the ratio of the pages he had read to the pages he had not read was 2:3. How many pages is this book

There are 400 pages in total. Do you have any difficult questions?
Dizzy, was preempted
Then I add the calculation method:
If you look at a quarter of the page on the first day, that is 25%, 60 pages on the second day, the two days add up to 2 / 5, that is 40%, and you look at 40% on the previous two days. Then 40% minus 25% on the first day leaves 15%, that is 60 pages on the second day, 60 = 15%. 60 divided by 15 equals 4, that is to say, 1% is four pages, then 4 times 100 is 400!
So 400 pages,

It is known that the set a = {2, the square of (a + 1), the square of a + 3A + 3}, and 1 belongs to the range of a finding the real number a

Solution 1) when (a + 1) & # 178; = 1, a = 0 or a = - 2, when a = 0, the square of a + 3A + 3 = 3, if there is no repeating element a = - 2, the square of a + 3A + 3 = 1, if there is no repeating element a = - 2, the square of 2) a + 3A + 3 = 1A + 3A + 2 = 0, a = - 1 or a = - 2, when a = - 1, the square of (a + 1) is 0, if there is no repeating element a = - 2, (...)

Xiaoqiang usually takes only 20 minutes to go from home to school by bike. As there are 2 kilometers of roads being repaired on the way, he has to walk with a cart. The walking speed is only 13 times that of cycling. As a result, it takes 36 minutes to get to school. How many kilometers does Xiaoqiang have from home to school?

If the walking speed is 13 times that of cycling, then the walking speed: cycling speed = 1:3, then in 2km, the time ratio = 3:1, then the walking time is two times more, so one is: (36-20) △ 2 = 8 (minutes), then the distance from home to school is 2 △ 8 × 20 = 5 (kilometers). A: Xiaoqiang's home to school is 5km

How many μ m is the thickness of zinc coating 275 G

The thickness of zinc coating on galvanized sheet is 275g, 38.5um if it is single-sided, and 19.25um if it is double-sided

It takes four hours for a car and five hours for a bus. The ratio of the speed of a car to that of a bus is ()

The distance L is the same. The two vehicles need different time. Assuming the speed of the cart is s and the speed of the trolley is s, the equation can be obtained
Cart L = 5 * s;
Trolley L = 4 * s;
That is, 5 * s = 4 * s;
That is s / S = 5 / 4
A: the speed ratio of a car to a bus is 5:4

How to solve four equations with five unknowns
A + B = 3. A + C = 1. A + D = 6. A + e = 4 find y + D =? Let's see if the equation has innumerable solutions, but we should be able to find y + D
Wrong, it should be B + e = how much

The equation has an infinite set of solutions
Let a be any real number
b=3-a
c=1-a
d=6-a
e=4-a
In this case: B + e = 7-2a, it can also be any real number

Practical problems of linear equation with one variable (2317:31:0) There are five Sundays in a month. The sum of the five Sundays is 75. What's the last Sunday of the month?