Find the integer solution of the system of inequalities: x-3 (X-2) is less than or equal to 8 and 5-2 / 1 x [less than] 2x. This is the system of inequalities... This problem is x without a multiplier sign

Find the integer solution of the system of inequalities: x-3 (X-2) is less than or equal to 8 and 5-2 / 1 x [less than] 2x. This is the system of inequalities... This problem is x without a multiplier sign

X-3 (X-2) less than or equal to 8, x greater than or equal to - 1
5-2 / 1 x [less than] 2 x more than 2
So the integer solution of the inequality system is greater than 2

Calculation: 1 and 4 / 17 * (this is the multiplication sign) (2 and 2 / 3-3 / 4) + 17 and 11 / 12 / (this is the division sign) 17 / 21

Original formula = 21 / 17 × (8 / 3-3 / 4) + 215 / 12 △ 17 / 21
=21/17×23/12+215/12×21/17
=21/17×(23/12+215/12)
=21/17×238/12
=21×14/12
=24.5

Is' / 'a multiplication sign or a division sign in mathematics?

Division sign

(2 / 1 * 3 / 1) + (3 / 1 * 4 / 1) + (4 / 1 * 5 / 1) + (2007 / 1 * 2008 / 1)

2/1*3/1=6/1=2/1-3/1
3/1*4/1=12/1=3/1-4/1
4/1*5/1=20/1=4/1-5/1
.
2007/1*2008/1=2007/1-2008/1
(2/1*3/1)+(3/1*4/1)+(4/1*5/1)+.(2007/1*2008/1)
=2/1-3/1+3/1-4/1+4/1-5/1.+2007/1-2008/1
=2/1-2008/1
=2008/1004-1=2008/1003

How to calculate 1 / 2009 × 2 / 2009 × 3 / 2009 × 4 / 2009 × 5 / 2009 ×·········× 2008 / 2009?
It's multiplication. It's better to have steps

=2008!/2009^2008

| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009 - 1/2008|

| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009 - 1/2008|
＝ 1/2-1/3 +1/3- 1/4 + 1/4 - 1/5 …… + 1/2008 - 1/2009
＝1/2+[(-1/3）+1/3］+[(-1/4)+1/4]+…… +[(-1/2008)+1/2008]-1/2009
=1/2+0+0+…… +0-1/2009
=1/2-1/2009
=2007/4018

Calculate 1 × 1! + 2 × 2! + 3 × 3! + 4 × 4! + 2008×2008!+2009×2009!

n×n!=(n+1)!-n!
1×1!+2×2!+3×3!+4×4!+… 2008×2008!+2009×2009!
=(2!-1!)+(3!-2!)+(4!-3!)+…… (2009!-2008!)+(2010!-2009!)
=2010!-1!
=2010!-1

Help me to do a math problem, use + - and multiply sign to work out the formula (34, 5, 6, 8, 9, 1, 2 = 2008)
Is the plus minus multiply sign used in the book

（34《*》5《*》6《-》8《-》9《+》1）《*》2＝2008

/Denotes a semicolon
If 1 / (2 * 3) + 1 / (2 * 3) + 1 / (3 * 4) + +1 / (9 * 10),
1/（1*2）=1/1-1/2,1/（2*3）=1/2-1/3,1/（3*4）=1/3-1/4,…… , 1 / (9 * 10) = 1 / 9-1 / 10, then: 1 / (1 * 2) + 1 / (2 * 3) + 1 / (3 * 4) + +1/（9*10）=1/1-1/2+1/2-1/3+1/3-1/4+…… +1/9-1/10=1-1/10=9/10
Excuse me: (1) 1 / (1 * 3) + 1 / (3 * 5) + 1 / (5 * 7) + +1（17*19）= _________
(2) In the sum formula 1 / (1 * 3) + 1 / (3 * 5) + 1 / (5 * 7) + Item 6 is_______ Then 1 / (1999 * 2001) should be the second______ Item

(1)1/（1*3）+1/（3*5）+1/（5*7）+…… +1 (17 * 19) = (1 / 2) [1 - (1 / 3)] + (1 / 2) [(1 / 3) - (1 / 5)] + (1 / 2) [(1 / 5) - (1 / 7)] +... + (1 / 2) [(1 / 17) - (1 / 19)] = (1 / 2) [1 - (1 / 19)] = (1 / 2) (18 / 19) = 9 / 19; (2) in the sum formula 1 / (1 * 3) + 1 / (3 * 5) + 1 / (5 * 7) + ...

Calculation formula: 1 / 2 + 1 / 2 * 3 + 1 / 3 * 4 +. 1 / 2008 * 2009 note: * is multiplication sign / semicolon

=1 / 2 + 1 / 2-1 / 3 + 1 / 3-1 / 4 +. + 1 / 2008-1 / 2009 (1 / 2 * 3 can be disassembled into 1 / 2-1 / 3)
=1/2+1/2-1/2009
=2008/2009