It s hard to talk about you

Solution 1. 80% of the whole journey in 3 hours

The whole process is 100%.

So a total of 3*100% 80%=hours.

Solution 2. The whole journey takes x hours.

then 80% is 3 hours and 100% is x hours.

So 80%:3=100%:x

x*80%=3*100%

x=3 so it takes hours.

Time = 3 80% = hours.

2) Full journey = 45 (1-80%) = 225 km, speed = 225 * 80% 3 = 60 km.

Also 22 60 = hours.

hours).

2.Speed: 45 20% 80 3 = 60 (km/h), 45 60 = hours. 3+ hours).

1: 3 hours of driving 80, then 100 takes 3 80 * 100 hours.

Two: easy to get: the remaining 20 miles are 45km, then the whole journey is 45 20 225

(1) Let the profit of store A be a percentage of the profit of store B as x, according to the meaning of the title, there is a = B * x, A * (1 + 25%) = B * (1-20%), and the solution is x=64%.

2) The cost of the first set is x, then there is (1 + 20%) x = 168, then, x = 140, and the other set is y (1-20%) y = 168, then, y = 210, with 210 + 140-168 * 2 = 14, so, earn 14 yuan.

4) If the turnover in the second quarter is x, then there is, (1+, x = 10,000, the growth rate in the fourth quarter is, that is, the fourth quarter is 10% higher than the second quarter, then the turnover in the fourth quarter is.

Supplemental answer. 1) Let the growth rate be x, then, 500 (1 + x) = 600, get, x = 20%, and in April it is 600 (1 + 20%) (1 + 20%) = 864

2) The money now is: 60%*150*earned, and the profitability is.

3) Set the refrigerator ** to x, then 2400*40%=x*24%, solution, x=4000

The two places are located at a distance of x kilometers.

x/9+60)*5=x

Because the distance is divided by time = speed, there is because two cars are traveling in the opposite direction, and the speed of the two cars and the time of the two cars = distance.

It's up to you to solve it.

Let's say there are x parts in this batch.

x divided by (15 2) - x divided by 9 = 3

Because the total amount divided by time equals efficiency, the difference between the two efficiencies is 3

Wait a minute, for the rest.

There are only 4 courses, but what about the other one?

The process of the second problem: the equation can become: (5x 9+300) = x both sides multiplied by 9 at the same time: 5x + 2700 = 9x

Shift: 4x 2700 x 675

Think of a project as a unit one. Shejia left for x days halfway. (1 75 + 1 50) (40--x) + x 50 = 1

Because A and B cooperate first, 2 efficiency and * cooperation time + efficiency of B alone * time done x = 1

Let B's efficiency be y kilometers, then A's hourly repair (1020 kilometers.

1020 The principle is the same as before.

The equation can be changed to 2x 15 - x 9 = 3

Remove the denominator and multiply both sides of the equation by 135 at the same time to get 18x--15x=4053x=405

x=135 (the solution of the first problem) do you understand the rest?

(1) A's profit is set to x, and B's profit is set to y, then there is (1+25%)x=(1-20%)y, launched, x=

2) The cost of profitable clothes is x, and the cost of loss-making clothes is y, then there are (1+20%)x=168, x=140;（1-20%）y=168，y=210；168-140 = 28, 210-168 = 42, so the loss is 42-28 = 14 yuan.

3) Set the selling price as x, 80% x = 80 * (1 + 40%), x = 140 yuan, 140-80 = 60, 60 80 = 75% profitability.

4) The conditions are incomplete and cannot be answered.

If it is sold at x yuan, the sales volume will be [40-(x 40)] = (80-x).

Then profit a sales volume (x purchase price) (80-x)(x 30) -x)2+110x-2400

（x-110/2）2+625

When x=110 2=55, A has a maximum value of 625, so the best selling price of this product should be 55 yuan for maximum profit.

If the cost is a, the list price is a(1+p%)

After the discount, ** is a (1 + p%) (1-d%), which is greater than or equal to a can ensure that there is no loss.

Column: a(1+p%)(1-d%)>=a

The solution: d%<=p% (1+p%)

The saving is 20% off, the original price = yuan.

2 * draw and defeat with square meters.

2* sq.m.

Flat-bent reed square rice.

6+ sqm.

1) Chaxiao 7*8 56 square meters.

7*4*2 56 square meters.

8*4*2 64 square meters.

56+56+64 176 sq.m.

2) 176* yuan.

7*8 56 sq.m.

7* square meters.

8* sqm.

56 + 56 + 49-16 145 sq.m.

Multiply by multiply plus 2 times and multiply by 2 = square meters.

2 (1) 8 times 4 + 7 times 4 and multiplied by 2 plus 8 times 7 plus 35 = 211 square meters.

2) 211 times the yuan.

3. Only the sum of the model 8 multiplied by plus 7 times multiplied by 2 plus 8 times staring at the mountain 7 plus 16 = 177 square meters.

Multiply by 4 times the cubic decimeter difference.

Length = 50 divided by 25 = 2 dm.

2* square meters of excitement The remaining lazy socks and bridge socks have to be eliminated.