Calculation: (1-3) * (3-5) * (5-7) *. * (2001-2003) * (2003-2005)

Calculation: (1-3) * (3-5) * (5-7) *. * (2001-2003) * (2003-2005)

（1-3）*（3-5）*（5-7）*.*(2001-2003)*(2003-2005)
=(-2)*(-2)*.*(-2)*(-2)
It mainly depends on how many times (- 2) are there
Namely: (2005-1) / 2 = 1002
That is, there are 1002 such numbers multiplied
Namely
（1-3）*（3-5）*（5-7）*.*(2001-2003)*(2003-2005)
=(-2)*(-2)*.*(-2)*(-2)
=(-2)^1002
=2^1002

The expression x > 2 and (3)

(x>2)&&(3<=3);

How can one and two and four and seven be equal to 24

(1-(2-7))*4((1-2)+7)*4((1+4)+7)*2(1+(4+7))*2((1+7)-2)*4(1+(7-2))*4((1+7)+4)*2(1+(7+4))*22*((1+4)+7)2*(1+(4+7))2*((1+7)+4)2*(1+(7+4))2*((4+1)+7)2*(4+(1+7))2*((4+7)+1)2*(4+(7+1))2*((7+1)+4)2*(7+(1+4))2*...

For the formula | X-2 | + 13, when x = -, the minimum value of the formula is two blanks

For the formula | X-2 | + 13, when x = - 2, the minimum value of the formula is 13
Do not understand can ask, help please adopt, thank you!

To process (complete) 2 and 4 / 15 times 9 times 1 and 5 / 12 equals
8 and 11:6 × 4 and 9:2-8 and 11:6 × 3 and 9:2=

① Original formula = 34 / 15 × 9 × 17 / 12
=34/5×17/4
=578/20
=289/10
=28 and 9 / 10
② 8 and 11:6 × 4 and 9:2-8 and 11:6 × 3 and 9:2
=6 / 8 / 11 (2 / 4 / 9-2 / 3 / 9)
=8 and 6 / 11

It is known that the polynomials AX2 + 2bxy + x2-x-2xy + y about X and y do not contain quadratic terms, so we can find the value of 5a-8b

∵ the polynomials AX2 + 2bxy + x2-x-2xy + y of X and y do not contain quadratic terms, ∵ a + 1 = 0, 2b-2 = 0, so a = - 1, B = 1, then 5a-8b = - 5-8 = - 13

The total mass of a bottle filled with water is 120g; the total mass of a bottle filled with alcohol is 100g. What is the mass of the bottle in the bottle
The total mass of a bottle filled with water is 120g; the total mass of a bottle filled with alcohol is 100g. What is the mass of alcohol in the bottle?
What is the mass of the bottle in the bottle

If the bottle mass is XG, the water mass is (120-x) g and the alcohol mass is (100-x) g
The density of water is 1g / ml, the density of alcohol is 0.8g/ml
The bottle volume is (120-x) / 1 = (100-x) / 0.8
The solution is x = 20g
Alcohol mass = 100-20 = 80g

5 / 24 + 3 / 8 + 7 / 12 '` 0.45 = 9 / () = () / 40 = () divided by 60 ································ 13 / 20 and 5 / 8

5/24+3/8+7/12=﹙5+9+14﹚/24=28/24=7/6
45 = 9 / (20) = (18) / 40 = (27) divided by 60
General score calculation 5 / 12 + 13 / 18 = 15 / 36 + 26 / 36 = 41 / 36
13/20+5/8=26/40+25/40=51/40

The sum of 11 out of 15 minus 1 out of 6 plus 1 out of 2 is calculated by a simple method

11/15-1/6+1/2
=37/30-5/30
=16/15

The second application of one yuan~
Star stores buy a batch of goods from the manufacturer at the price of 21 yuan per piece. The goods can be priced by themselves. If the price of each piece is a yuan, they can sell (350-10a) pieces. However, the Price Bureau limits that each piece of goods can not exceed 20% of the purchase price. If the store plans to earn 400 yuan, how many pieces of goods must be sold? How many yuan should each piece of goods be sold?

Known by
(a-21)（350-10a）=400;
a