Math problems in the second year of junior high school,,Trouble the specific process.。。 Thank you wi

I can't draw the picture, you should be able to understand it by drawing it yourself.

Solution:1When pq ab, i.e., ap=dq, let t=t, then 10-t=(10+6)-2t, and t=6

2.Because (10+6) 2=8, t<8, becomes an isosceles triangle in several cases (* is multiplication).

When ap=pq, (1) when 03. So it doesn't hold.

2) when 33) 6< t<8 because when t=6, pq ab can only be pq=aq, think of it from another angle, that is, ap=2dq, let the vertical start time at this time be y, 4-y=2*(4-2y), the solution is y=4 3, so t=6+4 3=22 3< p>

Question 1: AB distance 10cm p velocity 1cm sec p to end time 10s b-c-d distance is 10 + 6 = 16cm q velocity 2cm sec q to end time 8s so p stops when q reaches the end point.

So when Q catches up with P on C-D, that's their vertical time. That is, bp distance = bq distance - bc distance.

That is, t=2t-6 is solved to obtain t=6s

In the second question, we can get the qa distance = pq distance. If the figure APQ is an isosceles triangle, you can get the DQ distance = half of the AP distance.

That is, CD distance - (BQ distance - BC distance) = (AB distance - BP distance) divided by 2,10 - (2t-6) = (10-t) 2

The solution yields t=22 3 s

This is the correct answer to hope!

No picture! How can I help you solve it!

2、m=3，y=6m

3. Clever bend x+y=6, a function of filial piety.

x+y=20,5

3 all 5(1) If an average of x students can pass through one main gate and (x-40) students through one side gate per minute.

Solve equation 2 (x-40+x)=400 to get x=120, x-40=80

Answer: (2) Because of the congestion of students in an emergency, the way out is reduced by 20%, and on average, a main gate can pass through 120 · (1-20%) = 96 students per minute, and a side door can pass through 80 · (1-20%) = 64 students.

The building can accommodate a maximum of 4·6·45=1080 students, and it takes 1080 (2·96+64)= for students to be safely evacuated through 3 doors in case of emergency, which is less than 5 minutes.

Therefore, the construction of these 3 gates meets the safety regulations.

6.The first one asked:

Equation 1 x+y=400

Equation 2 60*（1-30%）*x+50）+40y=18400

Garment Profit = Number of Persons Number of Garments Made per Person per Day Profit per Piece

2) Surplus Cloth Profit = Direct Sales per Meter** Surplus Fabric

3) Garment profit + residual profit = 11800, column equation

4) When all the woven fabric is used for weaving clothes, the profit is greatest

8.Solution: (1) Set the time to be a puppy a minute, the piecework wage is b yuan, the time to make a car is c minutes, and the piecework wage is d yuan, which is derived from the title:

The solution is 480 x 800, when x = 480, w max = 1012<1100, the ad is fraudulent.

Question 5: 120 at the main gate, 80 at the side door, and the last five minutes are passable My answer is less than five minutes.

Let's say the side door passes through x people every minute.

x+x+40=400÷2

x=30 30+40=70

In case of emergency, all three doors are opened, and (70+70+30) passes through every minute: 80%=13652 24=1248 greater than 136 5=680, and cannot run out within the specified time.

So it doesn't meet the regulations.

The meaning is the third column of the second row.