The final exam is coming soon, so please help me review my math

1.Written as a fraction i.e. a 4 = cross multiplication 7a = to solve a = 8 70 = 4 35

2.A total of x hours, with one hour of rest, i.e. the travel time is (x-1) hours, s=vt=8*(x-1)=8x-8

3.Isn't that interesting......Right angle. The ratio of the three sides is about 3:4:5 and represents the sum of 4 2 5s.

4 2 5 means divide 4 into 5 equal parts, and take two of them [I don't know if you say so......

5 8 3 7 means 5 8 consecutive minus 3 7, and the number of consecutive subtractions when 0 is obtained [Ibid.......Hour = 60 minutes, 1 4 hours = 60 * 1 4 = 15 minutes, then it is the sum of 4 hours and 15 minutes and 716.

Subtract 59 in a row to get the number of times you can lose a row when 0.

8.Let's talk about it separately if you ask how it is calculated.

35=18: () is written as a fraction, which is 18 ?=35 So? =18 35 The same goes for 35=?20 So? =20*35=700 25=35, then? =25*35=875

40=35 So? =35*40=1400 The last empty is not understood ......

Decimeter = 4 cm Length: Width = 6:4 = 3:2 The ratio is.

1. 8 70 2. 8x-8 3. Right angle 4, 5, 4 hours and 15 minutes.

Sorry, I only understood a few, and I've just started my first year of junior high school.

2. 8x—x

3.Right-angled triangle.

5.4:15 a.m.

1) 8 70, simplified to 4 35;

2) 8 times (x-1);

3) Seeing that there are 90 degrees, write right angles without hesitation;

4) 2 5 4 means 4 2 5 add up, 4 2 5 means divide 4 into 5 equal parts, take two of them, 5 8 3 7 means 5 8 subtract 3 7, get the number of times when 0 is subtracted;

5) 4:15 a.m.;

6) Is 716 to the power of 59? Indicates what is the product of 59 716 multiplied by each other;

7) 59 equal parts divided into 716 parts, how much is each part;

8) How much can be seen as how much divided by how much, so the above can be turned into 35=18 ()=() 20=() 25=() 40. (The rest is up to you = = Actually, I'm not very sure about this .......)）

9) Decimeter = 4 cm (1 decimeter equals ten centimeters), 3:2,.

It's been a long time since I've turned a book... So I'm not very sure, and it's up to you how to choose.

<> I'm glad to answer your questions about the needy errands, please take Kai Nana early.

Solution: an+1=3an an+3

1 a(n+1)=(an+3) 3an=1 an+1 31 an} is a series of equal differences with 1 3 as the missing argument and 2 as the prime minister.

1/an=1/3(n-1)+2

1/3)×n-1/3+6/3

1/3)×n+5/3

1 3) n+(1 rebate 3) 5

1/3)×(n+5)

n+5)/3

So the stove posture. an=3/(n+5)

First empty: current price = 80 7 10 = 56

The second empty: current price = 72 7 10 = 72 10 7 = 720 7 The third blank: current price = 63 7 10 = 63 10 7 = 90 If you don't understand something, you can ask me, and please adopt it if you are satisfied. Thanks!

Fluffy bear current price: 80 * 7 10 = 56 yuan.

The original price of fluffy bees: 72 (7 10) = 102 and 6 7 yuan.

Original price of fluffy dolls: 63 (7 10) = 90 yuan.

From top to bottom.

I suspect not 72) 90

Current price Original price = 7 10, so the first empty is: x 80 = 7 10, x = 7 * 80 10 = 56; The others are so follows, 720 7 is approximately equal to yuan, and 90 yuan respectively.