The electricity cost of a factory in the first quarter is a yuan, and the water cost is 40 yuan more than 2 times of the electricity cost. In the second quarter, the electricity cost is saved by 10%, and the water cost is 38% more. Compared with the first quarter, the water and electricity cost of the factory in the second quarter is overspended or saved? How many yuan is overspended or saved?

The water and electricity cost of the factory in the first quarter is: a + (2a + 40) = 3A + 40 (yuan);
In the second quarter, the water and electricity charges are: a × (1-10%) + (2a + 40) × (1 + 10%) = a + 50 (yuan);
Compared with the first quarter, the water and electricity charges in the second quarter were overspent by a + 10 yuan
Solutions:
The first quarter's water and electricity fee = electricity fee a yuan + 2 × electricity fee a + 40;
Water and electricity charges in the second quarter = electricity charges in the first quarter × (1-10%) + electricity charges in the first quarter × (1 + 10%);
Let the second quarter of water and electricity - the first quarter of water and electricity, see is positive or negative, is a positive number is overspending
I suspect that my calculation is wrong, please LZ had better do it by himself

In the first quarter, a factory used m yuan of electricity, 40 yuan more than twice as much water as electricity. In the second quarter, it saved 15% of electricity and 38% more water,
Is the water and electricity cost of the plant in the second quarter overspent or saved compared with that in the first quarter, and how much overspent or saved?

Electricity charge in the first quarter: m water charge in the first quarter: 2m + 40 sum in the first quarter: 3M + 40
Electricity charge in the second quarter: (1-15%) M = 85% m water charge in the second quarter: (1 + 38%) * (2m + 40) = 276% m + 55.2
Sum of the second quarter: 361% m + 55.2 = 3.61m + 55.2
So the sum of the second quarter - the sum of the first quarter = 0.61m + 15.2
So the second quarter overspend (0.61m + 15.2) yuan

60 of X is equal to 90 of 200 minus x, help me make up a math problem

Car a goes from city a to city B at the speed of X km and arrives at city B in 90 minutes; if it goes at the speed of 200-x km and arrives at city B in 60 minutes, the speed is X
X/60=(200-X)/90 → 90X=（200-X）*60

Passenger cars and freight cars leave from a and B at the same time. Passenger cars travel 80 kilometers per hour and freight cars 64 kilometers per hour. After meeting, passenger cars continue to travel 4.5 hours to reach B. how many kilometers do the two cities meet

After the meeting, the journey of the bus is equal to that of the truck before the meeting
It is: 4.5 × 80 = 360 km
Encounter time: 360 △ 64 = 5.625 hours
Before the meeting, the bus went:
625 × 80 = 450 km
Distance between a and B: 360 + 450 = 810km

Who's bigger, 4 / 3 or 1 / 2? Why?

4 / 3 ＞ 1
1 / 2 < 1
So four out of three

Factorization of the Square-1 of 16A
Square-1 of 16A
The square of 4A - the square of 12ab + 9b

16a²-1
=(4a)²-1
=(4a+1)(4a-1)
4a²-12ab+9b²
=(2a)²-2(2a)(3b)+(3b)²
=(2a-3b)²

There are five boxes of fruit, each of which weighs 50 cattle. Now we are going to move it from the first floor to the third floor
There are five boxes of fruit, each box weighs 50 cattle. Now we need to move them from the first floor to the third floor. You can move them all at one time, or you can move a box each time, five times. Which way do you think can do more work for fruit? Which way needs to consume more energy in your body? Why?
Write clearly why!

W = FS = 50 * 5 * H = 250h (J). The work done on five boxes of fruits is the same. The second way consumes more energy, because the second way is far away

It is known that - 2A ^ XB ^ 3 and 1 / 3A ^ 2B ^ y are of the same kind. Find the value of polynomial 1 / 2x ^ 3-1 / 6xy ^ 2-1 / 3Y ^ 3

Is a similar term,
So x = 2
y=3
So the original formula = 4-3-9 = - 8

The density of mercury is 13.6 × 10 cubic kilogram per cubic meter. What is the ratio of mass to volume for any mass of mercury?

3 times of 13.6 × 10 kg / m3

A batch of fruit sold 60 kg on the first day, which is exactly two-thirds of the next day

Let the next day be X
2/3 X =60
X =60 / 2/3
X =90
Answer: .