Junior high school problems, junior high school math problems

The eggs of flies and mosquitoes can be dormant to survive the undesirable environment, and will reappear or hatch when the external environment is suitable.

Mosquitoes lay their eggs in moist places, especially in water.

Yeast is asexual budding reproduction and fission under suitable conditions, and sexual conjugative reproduction in adverse environments.

1. Mosquitoes hibernate. 2 The larvae of mosquitoes live in water. 3. Humid and stuffy place.

There are 1+12 in the first row

There are 2+12 in the second row

There is N+12 in row n

All seats are available in the sum of all seats.

1+2+3...n+12n

n(n+1)/2 +12n

n^2/2 + 25n/2

=(c-a) 2-4*(b-c)*(a-b)=0 has Vedic theorem: x1+x2=(k+1) 2 x1*x2=(k+3) 2x1-x2) 2=(x1+x2) 2-4*x1*x2=1x1+x2=-p x1*x2=-q

x1+1)+(x2+1)=-q (x1+1)*(x2+1)=p is long, width is a, b, and diagonal is c

a+b=k+1 a*b=1/4k²+1

c 2 = a 2 + b 2 = (a+b) 2-2*a*b=5 Vedic theorem: In a quadratic equation where the two roots are x1 and x2, then x1+x2= -b a x1*x2=c a

The absolute value of negative is that the absolute value of negative half is one-half, the opposite of the absolute value of negative two is still negative two, and the opposite of negative eight is eight.

In order of absolute value and inverse number, it is: -(8) |0＞-|2|3 and 1 in 4.

There is an absolute value symbol in front of minus 2.5, so we can see that there is a negative sign in front of the absolute value sign of minus 2, which is equivalent to turning minus 2 into a positive integer and then making it a negative integer, so the absolute value of minus 2.5 is ranked first.

3 and 4 parts = - (3 + 4 parts) = -3 +

8)>|1/2|>0>-|2|3 and 1 in 4.

Big to Small-(-8)" Do you think, you and Xiao Ming each have 10 yuan, he dropped the yuan, you dropped 2 yuan, then whoever has more left, then who is in the third year.

The absolute value is the distance to the origin, whether there is a negative sign in it, and it is positive when it comes out.

3 and 4 parts = - (3 + 4 parts) = -3 +

8)>|1/2|>0>-|2|3 and 1 in 4.

(-8) >1/2| >0 > 2|3 and 1 in 4.

Because the absolute value of negative is positive and greater than negative 2.

From largest to smallest: -(8),|1/2|，0，-|2|3 and 1 in 4.

The absolute value of a negative number is a positive number, and now the opposite number of a negative number is also a positive number.

1/2|=1 2 , 0, -3 and 1/4, -2| =2, -8)=8

So in descending order, it is: -(8) ,1 2| ,0,-|2|3 and 1 in 4.

7x+3-(6x-5)

x+8A: The difference between these two numbers is x+8

X's blind Bi Qi Mo Wu Qin Tangerine laughs at the number of the big three: 7x+3

Six times the number of x's smaller fives: 6x-5

The difference between two numbers.

7x+3-（6x-5）

7x+3-6x+5x+8

3 minus y the absolute value of the socks plus x+y is equal to 0, so the absolute value of 3 minus y = 0;The absolute value of x+y = 0 (the absolute value must be greater than or equal to 0) so Zen excitation, y = 3, x = -3

So, x-y=-9 -6=3 2 xy