Y = x2-2x-3 x (- [0,2] find the range

Y = x2-2x-3 x (- [0,2] find the range

y=x2-2x+1-4
=(x-1)2-4
So x = 1, the minimum is - 4
X = 0 or 2, y Max is - 3
So the range is [- 4, - 3]

Given the function f (x) = the square of x minus 2aX + 1, find the minimum value of the function from 0.5 to 2

f(x)=x^2-2ax+1=(x-a)^2+1-a^2
When a

The other line y = KX + B (k is not equal to zero) passes through point C (1,0), and the triangle AOB is divided into two parts

A (2,0), B (0,2). The straight line L: y = KX + B (k is not equal to zero) passes through the point C (1,0), ∧ K + B = 0. ① (1) point C is the midpoint of OA, and the area of two parts of triangle aobl is equal, then the slope of L passing through point B and BC is k = - 2, which is substituted into ①, B = 2

① 20 rational number operation problems. 2. 10 simplified evaluation problems. 3. 20 solving equations. 4. 20 one variable linear equations
It's not very simple, it's difficult. But the answer should be able to work out, can work out. Just give the formula

x+8=32 x+3x=48

Mathematical Olympiad of average
1. There are 18 grannies in the nursing home, with an average age of 75. There are 12 grandfathers, with an average age of 70. The average age of these old people is () years old
2. There are four numbers. Three numbers are added each time. The sum is 22, 24, 27 and 20 respectively. The four numbers are (), (), (), ()
3. Four teams collected tea. Team a, B and C collected 24 kg on average. Team B, C and D collected 26 kg on average. Team D collected 28 kg and team a () kg
4. The sum of a and B is 176. If C is added, the average of the three numbers is more than that of a and B. C is ()
(it must be completed on or before May 19, and the best answer will be decided on May 20 or 21)
(copy the title first, then fill in the blanks)
Please give reasons or formulas.

1. There are 18 grannies in the nursing home, with an average age of 75. There are 12 grandfathers, with an average age of 70. The average age of these old people is (73). 2. There are four numbers. Add three numbers each time, and the sum is 22, 24, 27 and 20. The four numbers are (9), (7), (4), (11). 3 and 4 teams collect tea, respectively

1. Simple method: 33 times 66 + 33 times 6-33 times 2103 times 2596 times 12542 times (20 + 5)
Elder brothers and sisters, help younger sisters! Now it's urgent

33*66+33*6-33*2
=2178+33*6-33*2
=2178+198-33*2
=2178+198-66
=2376-66
=2310
103*25
= 2575
96*125
=12000
42*(20+5)
=42*25
=1050

Congcong and Mingming buy books together. Congcong likes a story book and Mingming likes a picture book, but they don't have enough money. If Mingming lends money to Congcong to buy a story book, he has 30 yuan left. If Congcong lends money to Mingming to buy a picture book, he has 6 yuan left. The price of a picture book is four times that of a story book. How much money do they bring together?

Let them bring X Yuan in total
4(x-30)=x-6
x=38

What are the appellations of people aged 20, 30, 40, 50, 60 and 70 in ancient times?
call

20 weak crown, 30 standing, 40 not confused, 50 Zhiming, 60 ear Shun Huajia, 70 rare

How much is 250 times 8 minus 460 divided by 10

250*8-460/10
=2000-46
=1954

Through the teacher's education, I finally clear the purpose of learning, good learning attitude

Through the teacher's education, I finally clear the purpose of learning, correct learning attitude