How to calculate 67 times 168 / 169

How to calculate 67 times 168 / 169

67 times 168 / 169
=67*（1-1/169）
=67-67/169
=102 / 66 and 169

Simplify | x + 1 | - | 2x-1 | + | X-2|

x>=2,y=x+1-2x+1+x-2=0
0.5=

If the function f (x) = x2 + 2xtan θ - 1 is monotone on [- 1,3], then the value range of θ is ()
A. （-π2+kπ，-π3+kπ]∪[π4+kπ，π2+kπ）（k∈Z）B. [-π4+kπ，π3+kπ]（k∈Z）C. （-π2+kπ，-π4+kπ]∪[π3+kπ，π2+kπ）（k∈Z）D. [-π3+kπ，π4+kπ]（k∈Z）

If f (x) = x2 + 2xtan θ - 1 is a monotone function on [- 1, 3], then - Tan θ ≤ - 1 or - Tan θ ≥ 3 ∪ Tan θ ≥ 1 or tan θ ≤ - 3 ∪ (- π 2 + K π, - π 3 + K π)] ∪ [π 4 + K π, π 2 + K π) (K ∈ z), then a is selected

How should we teach the Mathematical Olympiad mathematical exercises from grade 4 to grade 5 in primary school

Capture their interests and preferences
Improve the learning atmosphere in class
Mobilize their enthusiasm
Don't rush yourself
Let them study in a relaxed and happy environment
Don't put too much pressure on them
We should improve their interest in learning

How much is 15 out of 4 times 10? Write the score

It's 75 out of 2
That's 37.5

1. A & # 178 / b multiplied by B / a = () (2) a / b multiplied by 1 / b = ()
2. Calculation
(1) B / A / B / 2A & # 178; (2) AC & # 178 / 3B times 9b / A & # 178; C
(3) - B / 7xy & # 178; △ 14ab / X & # 178; Y (4) x & # 178; + XY / X multiplied by 1 / x + y
(5) (xy-x & # 178;) / / X-Y / XY (6) 4x & # 178; - 1 / X & # 178; + X multiplied by X + 1 / 1-2x △ 1 / X
（7）（a²-a）÷a/a-1 （8）x²-1/y÷x+1/²
Second question, / denotes the fraction line

a a/b^2 b/a÷b/2a^2=b/a*2a^2/b=2a ac²/3b^3*9b/a²c=ac²*9b/3b^3*a^2c=3c/a -b/7xy²÷14ab/x²y=-(b*x^2 y/7xy^2*14ab)=-(x/98a) x²+xy/x*1/x+y=x*(x+y)/x*(x+y)=1...

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+…… +1000=?

There is a formula for this problem
n(n + 1)/2
1000(1000 + 1)/2
= 500(1000 + 1)
= 500(1001)
= 500500
Ask me if you have any questions

How is 1 3 4 6 equal to 24

6/（1-3/4）

I like reading books about Chinese history

I like reading the books about Chinese history.

In 1900, 1949, 1956, 1984, 2000, 2008, 2009 and 2020, there were () in ordinary years and () in leap years

The calculation method of leap year: the number of years in A.D. era can be divided by four, that is, leap year; the number of years divided by 100 but not by 400 is equal year; the number of years divided by 100 but not by 400 is leap year. For example, 2000 is leap year, but 1900 is not
Leap years: 1956, 1984, 2000, 2008, 2020
Normal year: 1900-1949