Help me do it, how do you do these questions?

The result of the formula is within the range of values on the left.

6100 2=12200 (only).

12200-400=11800 (only).

11800 + 6100 = 17900 (only).

A: A total of 17,900 chickens were sold in two months.

First, find the quantity in May = 2 * 6100-400 = 11800

Then find the sum of April and May 6100+11800=17900

6,100 chickens were sold in April, and 400 chickens were sold in May 2 times less than in April, so they were sold in May.

6100 2-400 12200-400 11800 chickens, sold in two months.

11800+6100 17900 chickens.

A x 2/7 = B x 3/10

A is 21/20 of B

If B is x years old, then A is 21/20 years old.

21/20xx 1/3-1x=6 4/3

x = 60 A: 21 x = 63 out of 20

Consider assuming that A's age is x, and B's age is, 1 3x-1 4y=6, and the solution is x=

1.Let A's speed be x km/h and the total distance is s, so A's total time is sx

B's time is (1 3*s) 2*x+(2 3s0) 7 9*x=43 42*(s x), so A arrives first.

2.The total distance is x, the speed of the passenger car per hour is x 10, the speed of the truck per hour is x 15, and the equation y*(x 10+x 15)=x has been solved by y hours when the two cars meet, and y=6When the bus meets, there are still 192 kilometers away from City B, and it can be concluded that 192 kilometers will cost 4 per hour, so the total distance is 192 4 * 10 = 480 kilometers.

1. Analysis process: There is a rule in this question type, that is, to convert the three lines of AB, BC, AC into the same line, in addition, the graph is very critical, and the graph of this question is slightly insufficient, so it affects the judgment of the answerer. Proof: Set AF

tA=s u, tB=1s 3 2u+2s 3 (7U9)=1s 6U+6S 7u=43s 42U, then T A is less than T B, and A arrives first.

s-192)/s/10=192/s/15,s=478