How many prime numbers are multiplied by 57? Such as the title

How many prime numbers are multiplied by 57? Such as the title

3*19

What is the formula for multiplication of prime numbers of 34

34=2*17

Which prime numbers multiply by 88

88=2*2*2*11.

A and B solve the equation [ax + by = 2] a correctly solves x = 3, y = 2, B misinterprets C, [cx-7y = 8], B obtains x = - 2, y = 2, and finds the value of a.b.c
Is there anything more detailed

Substituting x = 3, y = 2 into ① to get 3A + 2B = 2, substituting x = 3, y = 2 into ② to get 3c-14 = 8, C = 22 / 3, substituting x = - 2, y = 2 into ① to get - 2A + 2B = 2, ④ to get 5A = 0, a = 0, 10b = 10, B = 1, a = 4 / 5, B = 1, C = 22 / 3

One cubic centimeter is less than one liter?

1 cc = 1 ml = 0.001 L

First column equation solution application problem urgent! Fast! To the point
1. There is a ship with a carrying capacity of 800 tons and a capacity of 795 cubic meters. Now it is carrying pig iron and cotton. The volume of pig iron is 0.3 cubic meters per ton and that of cotton is 4 cubic meters per ton. How many tons of pig iron and cotton can we make full use of the carrying capacity and capacity of the ship?
2. There are two kinds of bonds, a and B, with an annual interest rate of 10% to 12% respectively. Currently, there are 400 yuan bonds with a profit of 45 yuan after one year. How many are the two kinds of bonds?
3. To process a batch of parts, party a first processes 8 hours, and then processes 1.5 hours with Party B to complete the task. It is known that Party B processes 2 parts less than Party A per hour, with a total of 350 parts. How many parts do Party A and Party B process per hour?
Come on, who is the first, as long as it is right, give points

1: Set iron x tons, cotton (800-x) tons
Then 0.3x + 4 (800-x) = 795
0.3X+3200-4X=795
-3.7X=-2405
x=650
800-X=150
650 tons of iron, 150 tons of cotton

6.78 × 10.1-0.678 how to calculate simply

=6.78×10.1－6.78×6.78=6.78×(10.1－0.1)=6.78×10=67.8

Limx approaches to (1-x) - 1 / x under 0 radical

LIM (x - > 0) [√ (1-x) - 1] / X Equivalent Infinitesimal Substitution √ (1-x) - 1 - X / 2
= lim(x->0) (-x/2) / x
= -1/2

Seventh grade mathematics classroom feedback Volume 2 solving problems with equations (1) question 7 and 8

The textbook is not the same, the title is not the same. You have to write out the title

Sequence (13 15:20:39)
In the known sequence {an}, A1 = 2, the sum of the first n terms is SN. For any natural number n ≥ 2, 3sn-4, an, 2-3 / 2S (n-1) is an arithmetic sequence
(1) Find the general term formula of sequence {an};
(2) If the sequence {BN} satisfies BN = 3Sn, find the first n terms and TN of the sequence {BN}

1、
When n ≥ 2, 3sn-4, an, 2-3 / 2 × s (n-1) form an arithmetic sequence, so 2An = 3sn-4 + 2-3 / 2 × s (n-1)
Because an = SN-S (n-1), 2 [SN-S (n-1)] = 3sn-3 / 2 × s (n-1) - 2
Therefore, Sn + 1 / 2 × s (n-1) = 2, that is, 2Sn + s (n-1) = 4
because
2Sn＋S(n-1)＝4
2S(n-1)+S(n-2)＝4
The subtraction of the two formulas is: 2An + a (n-1) = 0, so an = - 1 / 2 × a (n-1), n ≥ 2
So, when n ≥ 2, an = 1 / 2 × (- 1 / 2) ^ (n-2)
When n = 1, A1 = 2
2、
S1＝2,
When n ≥ 2,
Sn
＝a1＋a2＋.＋an
＝2＋1/2＋1/2×(-1/2)＋.＋1/2×(-1/2)^(n-2)
＝2＋1/2×[1－(－1/2)^(n-1)]/(1＋1/2)
＝7/3－1/3×(－1/2)^(n-1)
So, Sn = 7 / 3-1 / 3 × (- 1 / 2) ^ (n-1), (n = 1,2,...)
So, BN = 3Sn = 7 - (- 1 / 2) ^ (n-1), so,
Tn＝b1＋b2＋...＋bn＝7n－2/3×[1－(－1/2)^n]