Solve the math problem in the first year of junior high school, everyone helps, it s very urgent

So the money to buy cookies should be between 0-40 and it must be in multiples.

Because the rest of the money options are whole numbers.

There are 14 options

So choose B

A Let's take a look at how much money Xiao Gang has left: 100-48-52-60 = 20 yuan.

How many biscuits can you buy for 20 yuan, biscuits are yuan.

The amount of money left over when you buy one copy and the amount of money left over when you buy two copies is 20-13 = 7 yuan.

Because there is no decimal in the answer, it can only be 13 yuan to buy two biscuits, and the remaining 7 yuan.

Please! Thank you!

From the inequality equation of the title, it is obtained, x 80 13 6

The price to buy cookies is between 0 and 40, and since the options are whole numbers, the money to buy cookies needs to be multiples. The number of packs of cookies bought is between 0 and 6.

Option is b. Thank you!

b can buy up to 6 packs of biscuits, so that's 1 quick money left, and you can use the multiples of 1 yuan to get b

Because there is only 40 yuan left except for the bread, there is no option, that is, to buy an even number.

Then the remaining b

The front of b cost a total of 160

The remaining 40 are subtracted separately

See which one is divisible.

1.Plan to dig in ten days. So the original plan was to dig every day.

Because the construction was carried out one day first, and then four days earlier. Therefore, after changing the efficiency, the construction took a total of 10-1-4=5 days.

So after changing the efficiency, dig every day (

Fit: (2.)6 hours for A, 8 hours for B, and 12 hours for C.

So A injects 1 6. of the total amount of water per hour

B injects 1 8 of the total amount of water per hour

C discharges 1 12 of the total amount of water per hour

Because A and B open for two hours first, the remaining space in the pool is 1-7 12 for injection (1 6 + 1 8) * 2 = 7 12

In the end, A, B, and C started together, and it took a total of x hours.

1 8+1 6-1 12)*x=5 12 gives x=2

Combination: (1 6+1 8)*2+(1 8+1 6-1 12)*x=1 gives x=2

2. Set the water to 1 when it is full, and the pool can be filled only after opening the C pipe x hours.

2×（1/6+1/8）+1/12]x=1x=

(1) The total expenses for the first quarter were:

a+2a-40=3a-40

Total expenses for the second quarter were:

1-20%)a+(1+5%)(2a-40)=

So in the second quarter there was less 3a-40-(yuan.)

2) Substitute a=8000

Original = $802 less.

(1) Q1: Electricity Charge: A Water Charge: 2a-40 Q2: Electricity Charge: Water Charge:

The total utility bill in the first quarter was 3a-40 and the total utility bill in the second quarter was 3a-40> so the utility bill in the first quarter was more than the second quarter.

2) When a=8000, the second quarter is 802 yuan less than the first quarter.

(1) Less. Less yuan.

2) 798 yuan less.

43.Let the other formula be (ax+b) and multiply by (x+2) to get ax 2+(2a+b)x+2b=x 2-kx+3, so a=1,b=

So k=