When a pile of cement is transported to the construction site, two fifths of the ton is used for building the wall, three fifths of the ton is used for paving the ground, and one tenth of the ton is left (1) How many tons of cement are used? (2) How many tons of cement are delivered?

Hello!
2 / 5 + 3 / 8 = 16 / 40 + 15 / 40 = 31 / 40 tons
There are 31 / 40 + 1 / 10 = 35 / 40 = 7 / 8 tons
If you don't understand this question, you can ask. If you are satisfied, remember to adopt it
If you have any other questions, please take this question and send it to me. Please understand
I wish you progress in your study!

The center angle of the sector AOB is 120 C, and the motion (vector) OC = xoa + yob on the arc AB, and the maximum value of X + y is obtained
OA=1

I'm just going to talk about the general idea. I can't find the symbol
Because the length of OC module is 1, we can get the square of X + the square of Y - x * y = 1
Using the square of inequality x * y ≤ (x / 2 + Y / 2)
Square of column (x + y) ≤ 1 + 3 * (x / 2 + Y / 2)
The maximum value is 2

There are 210 tons of yellow sand to be transported to the construction site. The first time, 40% of the total amount will be transported. How many tons will be transported to the construction site?

What's the total number of the first shipment

The linear equation of 3x-4y + 1 ≡ 0 with respect to Y-axis symmetry is

[solution] suppose P (x, y) is any point on the line 3x-4y + 1 = 0 with respect to Y-axis symmetry, then its point Q (- x, y) with respect to Y-axis symmetry must substitute Q (- x, y) on the line 3x-4y + 1 = 0 into the equation of the line 3x-4y + 1 = 0 to get: 3 · (- x) - 4Y + 1 = 0

There are 320 male workers and 200 female workers in a factory. How many more male workers than female workers? How many fewer female workers than male workers
Five minutes, quick, quick, quick, quick

More male workers than female workers (320-200) △ 200 = 3 / 5
The number of female workers is less than that of male workers (320-200) △ 320 = 3 / 8

Given the square of X-Y = 12, X-Y = 2, find the square of X + the square of Y
Help to do it! ~ thank you, speed

(X-Y) (x + y) = 12, so x + y = 6, then x ^ 2 + y ^ 2 + 2XY = 36 (1) x ^ 2 + y ^ 2-2xy = 4 (2) (1) + (2) SO 2 (x ^ 2 + y ^ 2) = 40, the square of X + the square of y = 20

There are 82 members in the school chorus, of which the number of female members is more than twice that of male members. How many male and female members are there

Suppose there are x male players, then there are 2x + 4 female players
x+2x+4=82
3x=78
X = 26
So there are 26 male players and 82-26 female players = 56
A: there are 26 male members and 56 female members in the chorus

Factorization x2-3x-1
How to factorize

X2-3x-1 = [x - (3-radical 13) / 2] [x - (3 + radical 13) / 2]

There were 325 male and female students. In the new school year, there are 25 more male students and 5% fewer female students. The total number has increased by 16. How many male students are there now?

There are x boys
x+25+(325-x)(1-5%)=325+16
x+25+325-x-16.25+0.05x=341
0.05x=7.25
x=145
145 + 25 = 170
So now there are 170 boys

The square of 3x - (the square of X + the square of Y) - the square of Y
5 (2x-7y) - 3 (4x-10y) half (the square of a-b) + one third (the square of a-b) + one sixth (the square of a + the square of B)

(x \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\1 (A & # 178; + B & # 178;) = 2 / 1A & # 178; -

When a pile of cement is transported to the construction site, two fifths of the ton is used for building the wall, three fifths of the ton is used for paving the ground, and one tenth of the ton is left (1) How many tons of cement are used? (2) How many tons of cement are delivered?