50 points for math and geography questions in the first year of junior high school

1.The velocity of A is x, and the velocity of B is y.

Because the distance is equal no matter how you go, the equation is established: y*1+20=x*1, and y*(15 60+1)=x*15 60, and the two joint solutions give the following formula: A is 25 km/h and B is 5 km/h.

2.Africa is known as the continent (plateau continent and tropical continent). The distribution of African climate is characterized by symmetrical distribution from north to south with the equator as the axis. Topographic characteristics: high in the east and south, low in the north of the west, and the terrain is inclined from southeast to northwest.

3.What are the world's best in Africa? How did it come to be?

The Great Rift Valley, the largest rift zone in the world, is caused by the splitting of the African plate. The Sahara Desert, the largest desert in the world, is controlled by the subtropical high pressure zone. Lake Tanganyika is the deepest and narrowest lake in Africa and the second deepest lake in the world for the following reasons:

Fracture sagging. The largest basin, the Congo Basin, is caused by tectonic movements that cause the basin to rise and the lake to leak out.

4.The oil resources of West Asia are mainly distributed in the (Persian) Gulf and coastal areas (Iran), (Iraq) (Kuwait) and (Saudi Arabia), and the four countries are important oil producers in the world.

5.West Asia is one of the main settlements of the (Arab) peoples of the world, who profess Islam.

1 A: 5 12km min

B: 1 12km min

2 Tropical continent (plateau continent), topographic characteristics: plateau continent, high in the east and low in the west Climatic characteristics: tropical climate, symmetrical distribution from north to south.

3 Largest deserts controlled by the subtropical high.

The largest basin is the Congo Basin.

The largest rift zone, the Great Rift Valley, is a plate extensional fault.

The tropics are the largest and most of them are between the Tropic of Cancer, with the continents being the second.

4Persian Gulf: Saudi Arabia, Iraq, Iran, Kuwait.

5 Arab.

1 A: 5 12km min

B: 1 12km min

2 Tropical continents, plateau continents, high in the east and low in the west.

3 Largest deserts controlled by the subtropical high.

4. Persian Gulf: Saudi Arabia, Iraq, Iran, United Arab Emirates, Kuwait.

5 Islam.

2. Africa is called a plateau continent, and its climate distribution is characterized by changes from the equator to the north and south.

1.A is x, B is y.

y*1+20=x*1

y*（15/60+1）=x*15/60

If I'm not good at liberal arts, I can't do it

I.1Add the two formulas to give us 6x=42, so x=7, and bring in the formula: 14 + y = 23, so y = 9

Answer: x=7, y=9

2.The sum of the two formulas yields: 6x=18, so x=3, and the addition of the equation yields: 9+2y=13, so y=2

Answer: x=3, y=2

3.Formula 1 - 2 * 2 gets: x = -5, bring in formula 1 gets: -15-2 y = 9, so y = -12

Answer: x=-5, y=-12

4.Formula *2-formula *3 gets: -5x=-4, so x=4 5, bring in formula: 8 5-3y=1, so y=1 5

Answer: x=4 5, y=1 5

II.1The sum of the two formulas yields: 7x=21, so x=3, and the addition of the equation yields: 12-y=14, so y=-2

Answer: x=3, y=2

2.One-two: y=15, bring in one: 1 2x-30=7, so x=74

Answer: x=74, y=15

III. 1Formula *3 - Formula 2 yields: 19n=19, so n = 1, and brings in equation 1 to get: 2m + 7 = 5, so m = -1

Answer: m=-1, n=1

2.Formula *2-2 gets: -13v=26, so v=-2, bring in formula 1: 2u+10=12, so u=1

Answer: u=1, v=-2

3.Add the two formulas to obtain: 2 3x=-7 6, so x=-7 4, and bring in the formula: -7 12-y 7=-3 2, so y=77 12

Answer: x=-7 4, y=77 12

Fourth, simplify the formula to obtain: x+5y=0, add this formula and the two formula to get: 3x=7, so x=7 3, bring in the two formulas to obtain: y=-7 15

Answer: x=7 3, y=-7 15

Fifth, the original formula is: 2V+T=3, 3V-2T=3, a formula *2 + two formulas: 7V=9, so V=9 7, bring in a formula: 18 7+T=3, so T=3 7

Answer: v=9 7, t=3 7

6. Let the two digits and tens be x and the single digit y, that is, the two digits are 10x+y

Because the number in the 10 digit is 2 times the number in the digit, x=2y

Because if you exchange the positions of the ten digits and the single digits, then the resulting number is 36 smaller than the original number, so (10x+y)-(10y+x)=36, simplified to x-y=4, and bring x=2y into this equation, get: 2y-y=4, so y=4, so x=2y=8

Answer: The original two-digit number was 84

One. The following system of equations is solved using addition, subtraction, and subtraction.

Addition and subtraction is a method of solving an equation by expanding or reducing the multiple of a certain formula so that it is the same as the absolute value of the factor of one of the variables of another formula, so as to add or subtract to achieve the purpose of elimination.

Answer: The original two-digit number was 84.

p(-x2-1，|x-1|)

Because -x2-1 is always less than 0, it can only be in the second or third quadrant, and if you look at the absolute value of x-1, it is always greater than 0, so it can only be in the binomial limit.

The key is to have a discussion about X-1.

Solution:1Because |x+3 1/2|with |y-2 1/2|Numbers are inverse to each other, so:

x+3 1/2|+|y-2 1/2|=0 and because: |x+3 1/2|Greater than or equal to 0, |y-2 1/2|Greater than or equal to 0 so: |x+3 1/2|=0，|y-2 1/2|=0So:

x+7/2=0,y-5/2=0

So: x=-7 2, y=5 2

So: x+y=-7 2+5 2=-1

2.Divide by 25 and put the remainder backwards.

So it is: 11001

3.Because |x+1|+（y-3）²=0

And because:|x+1|Greater than or equal to zero, (y-3) greater than or equal to zero so: |x+1|=0，（y-3）²=0

So: x+1=0, y-3=0

So: x=-1, y=3

So: x to the power of y = (-1) = -1

4.Black q=-12, red q=12 red 3=3 black a=-1(-12)*(1)*3-12=36-12=24 is a non-negative equation, and the equations he gives about x and y are all non-negative numbers, and the sum is zero, so the values of both equations are zero. The questions on the exam are all like this.

1 |x+3 1/2|>=0;|y-2 1/2|>=0;are inverse numbers to each other, i.e., |x+3 1/2|+|y-2 1/2|=0, then there must be.

x+3 1/2|= |y-2 1/2|=0, which yields x=-3 and 1 2;y=2 and 1 2,x+y=-1;

Your 3 1 2 means "3 and 1 2", and if it is 31 2, the result is -5 ).

2 Decimal to r: Divide by r remainder.

2 25 remainder.

2 12 1 Low.

2 0 1 high.

Hence 11001

3 Similar to 1, both are greater than or equal to 0, and the sum is 0, so x+1=0, (y-3) =0x=-1, y=3

Therefore x to the power of y = (-1) = -1

1. x<-2

2.(1) The selling price of each piece in May is RMB, because the turnover in May is (3b=

2) Eggplant Oak Amount in May - Turnover in April = (>0, so it increased in May.

3.（5/3a^2b-10/3a^2b^2+1)*(

Question 1 x<-2

Question 2 1) According to the title, the single selling price in May is yuan, then, the turnover is the single selling price * number of pieces = 3 (yuan: (yuan, where c 5.

2) The turnover of the liquid in April is bc, and the turnover ratio between April and May is different: bc-(, where C 5, then < 0, so B (Sun Xuwu 0, that is, the turnover in May is increased compared with that of Siyoula.

Question 3 Your description is a bit inaccurate, what I made according to the rules is [ -3a 2(b 2)+6a 2b-1] [9a (2b 2+2b)+3a 2b].

1；x<-2

2；Solution: (1) The unit price in May is (, and 3b pieces are sold, then the turnover in May is: single liter round price * number of pieces = (early aging; where (c>5).

2) The turnover in April is BC, and in May it is (; So just compare (with the size of c; c>5, then (>c; Therefore, the turnover in May is higher than that in April.

3；Solution: (5 3a 2b-10 3a 2b 2+1)*(5b-10+3a 2b 2) 3a 2b 2]*(ab 5)(10-3a 2b 2-5b) (15ab)The third question of the first quarrel and open the letter, your description may be a little vague, I don't know if it is done right; The first two questions should be fine!

Hee-hee......

<-22.(1)(c*4/5-2)3b

2)(c*4/5-2)3b-bc=bc*7/5-6bb(c*7/5-6)

Because Sendong Xunyu C>5, C*7 5>7, C*7 5-6>1>0, (C*4 5-2) 3b-BC>0, (C*4 5-2) 3b>BC increased in May.

3.(This Changku5 3a 2b-10 3a 2b 2+1)*(1 3a 3b 2+2 3a 3b 3-1 5ab

1 x is not equal to 0

2 (1)3b(

2) bc set the pickpocketing state c as the manuscript is rotten 6

6b6b is less than increased.

(1) How much is it per share on Thursday**? == Meta.

2) What day of the week was the highest stock price? How many dollars?

Monday, Tuesday, Wednesday, Thursday, Friday.

So Tuesday was the highest, yuan.

3) This weekend **** or ** compared to last weekend?

** Meta.

(1) How much is it per share on Thursday**?

2) What day of the week was the highest stock price? How many dollars?

Tuesday's highest is ($.

3) This weekend **** or ** compared to last weekend?

Yuan)** Yuan.

(1) (yuan).

Yuan) (2) (Yuan.

3) This weekend **** or ** compared to last weekend?

Yuan)** Yuan.

Degrees, minutes, and seconds are all in the base 60 system, which can be compared to the minutes and seconds in time.

Similarly, in this question 60°35 = 60+35 60=the same 70°53 3 In order to avoid too much error, you can replace it with the same bit 70°53 =(70+53 60)°= and then you know the sprinkle. --This can be borrowed from the above. Avoid making mistakes by swapping them into seconds.

Population density = total population area so 20w 1000 = 200 read more textbooks, read a book and basically know.

Multiplying 60 in a degree is a fraction. In multiplying by 60 into seconds. So 60 ° 35 >

As for 70°53 3, divide the degree by 3 first, add the remaining degree components with 53, divide by three, and then divide it into seconds and continue to divide by three. The result is 23 degrees, 37 minutes and 40 seconds.

Question 1: 60°35 vs. Comparison size.

Question 2: 70°53 3= 23°38 = Question 3: Population density = number of people Area = 200,000 1000 = 200 people square kilometers.

Units are unified.

The one above is good!