Party A and Party B work together to make a batch of parts and complete the task within 24 days. It is known that Party A makes 5 more parts per day than Party B, and Party B asks for 9 days' leave in the middle of the process, so Party B gets the number of parts It's exactly half of A. what's the total number of this batch of parts?

Party A and Party B work together to make a batch of parts and complete the task within 24 days. It is known that Party A makes 5 more parts per day than Party B, and Party B asks for 9 days' leave in the middle of the process, so Party B gets the number of parts It's exactly half of A. what's the total number of this batch of parts?

Quantity a = 5 + quantity B / day
So: the number of 24 days a = (the number of 15 days b) is twice > >
24 (5 + b) = 30 b > >
B = 20 / day, a = 25 / day
Total number = 24 days a + 15 days b = 600 + 300 = 900

Solve the equation 2x + 1 = 7; (2) 3-3x = 8x-2

A and B have two grain warehouses. A is three times as much as B. If a transports 240 tons and B transports 40 tons, then a and B are equal. How much grain does a and B have
This is the problem of primary school age 4, can you use a simpler method

Solution (1) a comprehensive formula
Because a is three times as much as B, so a is twice as much as B. after a transports 240 tons and B transports 40 tons, a and B are equal, so a is 200 tons more than B, and a is 200 tons more than B, so one time is 100 tons
(240-40)÷(3-1)=100
100×3=300
Answer: a warehouse original 300 tons of grain, B warehouse original 100 tons of grain
Solution (2) the solution of a series of equations
If warehouse B has x tons of grain, warehouse A has 3x tons of grain
According to the meaning of the title, the equation is
3X-240=X-40
The solution to this equation is
X=100
3X=300
A warehouse original 300 tons of grain, B warehouse original 100 tons of grain

Solving equation 0.7x/3 = x / 7-1

0.7x/3=x/7-1
Multiply by 21
4.9x=3x-21
1.9x=-21
x=-210/19

2/3 4/3 19/9 3 ( )

2/3=6/9
4/3=12/9
19/9=19/9
3=27/9
It can be found that the denominator is 9 and the numerator is 6, 7 and 8 in turn
The denominator of the next number is 9, and the numerator is 27 + 9 = 36
So the next number is 36 / 9 = 4

If {an} is an equal ratio sequence and Sn = 3N + R, then R=______ ．

∵ {an} is an equal ratio sequence, and Sn = 3N + R, ∵ A1 = S1 = 3 + R, ∵ A2 = s2-s1 = (9 + R) - (3 + R) = 6, ∵ A3 = s3-s2 = (27 + R) - (9 + R) = 18. From the equal ratio sequence, 62 = 18 (3 + R) can be obtained, and the solution is r = - 1, so the answer is: - 1

Mr. Chen wants to take a sum of money to Xinhua Bookstore to buy a set of books with upper and lower volumes. If he only buys the first volume, he can buy exactly 10 books; if he only buys the second volume, he can buy exactly 15 books; if he buys both the upper and lower volumes, he can buy exactly 10 books______ Set

A: if you buy both the upper and lower volumes, you can buy 6 sets. So the answer is: 6

Verification: 1 + 1 / A + (a + 1) (/ AB + (a + 1) (B + 1) / ABC + (a + 1) (B + 1) (c + 1) / ABCD = (a + 1) (B + 1) (c + 1) (D + 1) / ABCD
1+1/a+(a+1)(/ab+(a+1)(b+1)/abc+(a+1)(b+1)(c+1)/abcd=(a+1)(b+1)(c+1)(d+1)/abcd.

Divide on the left, or open the bracket on the right
(1) Left side = ABCD / ABCD + BCD / ABCD + (a + 1) CD / ABCD + (a + 1) (B + 1) d / ABCD + (a + 1) (B + 1) (c + 1) / ABCD
=[abcd+bcd+(a+1)cd+(a+1)(b+1)d+(a+1)(b+1)(c+1)]/abcd
=[(a+1)bcd+(a+1)cd+(a+1)(b+1)d+(a+1)(b+1)(c+1)]/abcd
=[(a+1)cd(b+1)+(a+1)(b+1)d+(a+1)(b+1)(c+1)]/abcd
=[(a+1)(b+1)d(c+1)+(a+1)(b+1)(c+1)]/abcd
=Right side
(2) Right = [(a + 1) (B + 1) (c + 1) d + (a + 1) (B + 1) (c + 1)] / ABCD
=[(a+1)(b+1)c+(a+1)(b+1)]/abc+(a+1)(b+1)(c+1)/abcd
=[(a+1)b+(a+1)]/ab+(a+1)(b+1)/abc+(a+1)(b+1)(c+1)/abcd
=(a+1)/a+(a+1)/ab+(a+1)(b+1)/abc+(a+1)(b+1)(c+1)/abcd
=Right side

2 3 4 5 6 = 16, fill in the calculation symbol in the blank

【2*3-4】*5+6= 16

Let a be an M * n matrix and B be an n * m matrix
emergency

I'm afraid your conclusion is wrong
a=[1 ,2,3; 4,5,6];
b=a'
c=a*b=[22 28; 49 64]
|ab|=|c|=det(c)=36!=0.