Math problems, hurry! Good guy say it

Analysis: There is a question to know the relationship between the original ** and the third price reduction. If the original ** is A, then the ** after the increase is ** after the third price reduction.

Solution: The percentage of ** after the third price reduction to the original ** is = the sales before the price reduction is 100a, the sales of the first price reduction are The sales of the second price reduction are The sales of the third price reduction are Therefore, the total sales of the new plan are 100a, so the new plan is more profitable.

1) Set the original price to a yuan, 1-30%)3 a=; 2) Sales at the original price = 100a yuan; Sales according to the new plan = 10 30%) + 40 yuan, so it is more profitable to sell according to the new plan.

The absolute value is the opposite of it: non-positive (or fill in: negative and 0).

The opposite number is the number of its own: non-negative (or fill in: positive and 0).

The reciprocal is the number of its own: 1, -1

Negative and 00 (depressed, seen as an absolute value is himself).

1 and -1

1、m＞02、n＜0

3. When n=0, m is arbitrary.

y=3x+8

When x=0,y=8, i.e., the coordinates of the intersection point with the y-axis (0,8)When y=0,x=-8 3, i.e., the coordinates of the intersection point with the x-axis (-8 3,0).

1.There are x people, and each person shakes hands with x-1 person, so that x(x-1) is the total number of sub-state annihilations that each person has shaken twice, so the imitation is divided by 2. So:

x(x-1)/2=15，x=6

2.As in the first question, since each team has to play twice, do not divide by 2. Namely:

x(x-1)=90, x=10 yo xi, done

5+1=6 (good key people) 6 people.

2) 90 2 = 45 (field).

9 + 1 = 10 (Yuming Qiaohuai Mill Team) 10 teams.

1.A total of 6 people attended the party. The first Shen Kai Chong shook 5 times, the second person shook 4 times, the third person shook 3 times, the fourth person shook 2 times, and the fifth person shook 1 time, totaling = 5 + 4 + 3 + 2 + 1 = 15

2.A total of 10 teams attended the party. Sun Que is the same as above, total = (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9) 2 = 90

1. The independent variable is the depth, and the dependent variable is the temperature of the depth reached.

2, t=2 x=5, y=

The argument is x

The dependent variable is yx=5 and t=2

So y=