1+2-3-4+5+6-7-8+9+10-… +2014, how much?

1+2-3-4+5+6-7-8+9+10-… +2014, how much?

(1 + 2-3-4) + (5 + 6-7-8) + (9 + 10-11-12) +. + (2009 + 2010-2011-2012) + 2013 + 2014 = - 4-4-4 -. - 4-4 + 2013 + 2014 (a total of 503 - 4) = (- 4) * (2012 / 4) + 2013 + 2014 = - 4 * 503 + 2013 + 2014 = - 2012 + 2013 + 2014 = 2015, your adoption

1 × 1 / 2 plus 2 × 1 / 3 plus 3 × 1 / 4 plus How much is one in 2013 × 2014

The original formula = (1-2 / 1) + (1-3 / 2) + (1-4 / 3) + +(1 / 2013-1 / 2014)
=1-2 / 1 + 2 / 1-3 / 1 + 3 / 1-4 / 1 + +1 / 2013-1 / 2014
=1-1 / 2014
=2013 / 2014

After two price cuts, the retail price of a commodity is reduced to half of the original price. It is known that the percentage of two price cuts is the same. How about the percentage of each price cut? (accurate to 1%, 2 = 1.414)

Suppose the original price is 1, then the current price is 12, then the equation is: 1 × (1-x) 2 = 12, the solution is: X1 = 0.293, X2 = 2.414, X2 = 2.414 does not conform to the meaning of the question, x = 0.293 ≈ 29%, a: the percentage of each reduction is 29%