Solve the problem, fill in the blanks as long as the answer, and the application question needs to b

Fill in the blanks 10,77

Application problem 3, because the diameter of 3 small circles = the diameter of the large circle, so the small r is 1 3 of the large r, that is, each small circle is 1 9 of the area of the large circle, so the remaining area = 36 (1-7 9).

Application question 5, sell 60% difference of 84 yuan, sell out of profit of 372 yuan, then 40% should be sold 372 + 84 = 456, total income: 456 40% = 1140 yuan Cost: 1140-372 = 768 Quantity:

1140 pieces, the purchase price of US branches: 768 120 = yuan.

In application problem 6, if the speed ratio is 2:3, then the time ratio is 3:2, from 10:

22 to 10:30 for 8 minutes, then 8:30 to grandma's house 8 2 3 = 12 minutes, the same way, 11:

30 It takes 30 2 3 = 20 minutes to get home. 1, 30 + 12 = 42 minutes, that is, 8:42 to grandma's house.

50, so 50-46 = 4 minutes, American minute travel: 300 4 = 75 meters, home sharing: 50-22 = 28 minutes, total distance = 28 75 = 2100 meters.

Calculation question 4: Original formula = (101 2-100 2) + (99 2-98 2) + ....3^2-2^2)+1^2=101+100+99+98+……2+1=（101+1）×101÷2=5151

After the application of problem 5, the square area = 10 10 = 100, the rope length is 5 meters, then the activity radius of the sheep is 5 meters, because the center of the circle is on the edge of the square, so the two sheep can each eat a semi-circle of grass, together to eat a whole circle, can not eat is: square meters.

1) A loom weaves 200 4 2 = 25 meters in one hour, so 480 8 25 = hours = 2 hours and 24 minutes 2) One day inspection: 1952 within 16 = 122 meters So 122 meters should be checked every day.

3) Each box of cow milk: 15 5 = 3 yuan 3 * 4 = 12 yuan 12 (4 + 2) = 2 yuan 3-2 = 1 yuan.

4) 15*3-10=35 minutes 35+15=50 minutes, I hope it can help you!!

(1) Let the quantity of A x, the quantity of B y, x+y=40

15520 340x+420y 15630 solution 14y=24, x=16

y=25,x=15

2) Let u be about the profit of (x,y), i.e. u=(390-340)x+(500-420)y=50x+80y

If x+y=m, u=50m+30y=80m-30x=65m+30(y-x), it can be seen that when the y-x difference is the largest, that is, x=0, the profit is the largest.

[It is expected that the cost of the two toys will not be less than 15,630 yuan and not higher than 15,520 yuan] is not written down.

It's you again! You're looking for someone to help you with your homework, and you've just picked a wrong equation, and you're going to end up with nothing in your studies!

Wow, how old is the kid this year? Also line segment diagram, I haven't seen a line segment diagram for 20 years.

If you actually buy x boxes of colored chalk, there are 4x boxes of white chalk, depending on the topic.

5*（x+2)=4x-2,x=12

4x=48 buys a total of 48+12=60 boxes.

What grade do you understand?

r'(x)=

r(x)=∫r'(x)dx

r(0)=0

c1=0r(x)=

c'(x)=5

c(x)=∫c'(x)dx

5dx5x+c2

c(0)=0

c2=0c(x)=5x

Profit: l(x)=r(x)-c(x)==

Maximum profit point: x = 250

Maximum profit: 25 million yuan.

f(x)=（

Finding the maximum value of f(x) is a problem.

f（x）= +25x -5 x

Maximum point: -b 2a = 20