tính nhanh nhất 2013*2+98*2013
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2013*2+98*2013 = 2013 * ( 2 + 98 ) = 2013 * 100 = 201300
tick mik nha mik tick lại cko
= ( 1 + 2 + 3 + 4 +.....+ 99 ) x (2013 x ( 3 - 2 ) - 2-13 )
= ( 1 + 2 + 3 + 4 +......+ 99 ) x ( 2013 - 2013 )
= ( 1 + 2 + 3 + 4 +....+ 99 ) x 0
= 0
(1-2+3-4+.....-98+99)x(2013x6-2013-2013x5)
=(1-2+3-4+....-98+99)x[ 2013x(6-1-5)]
= (1-2+3-4+....-98+99)x(2013x0)
= (1-2+3-4+....-98+99)x0 = 0
=> B=2013. (1+\(\frac{1}{1+2}\) +\(\frac{1}{1+2+3}\) +...+ \(\frac{1}{1+2+3+...+2012}\))
=>B= 2013.(\(\frac{2}{2}\) + \(\frac{2}{2.3}\) +\(\frac{2}{3.4}\) +...+\(\frac{2}{2012.2013}\))
=>B= 2013.2.(\(\frac{1}{1.2}\) + \(\frac{1}{2.3}\) +\(\frac{1}{3.4}\) +...+\(\frac{1}{2012.2013}\))
=>B=4026. (1-\(\frac{1}{2}\) +\(\frac{1}{2}\) -\(\frac{1}{3}\) + ...+\(\frac{1}{2012}\) - \(\frac{1}{2013}\))
=>B=4026.(1-\(\frac{1}{2013}\))
=>B=4026.\(\frac{2012}{2013}\) => B=2.2012=4024 Vậy B=4024
a)
=347x6+347x3+347x1
=347x(6+3+1)
=347x10
=3470
b)
=2013x3+2013x7
=2013x(3+7)
=2013x10
=20130
a)
= 347 x 6 + 347 x 3 + 347 x 1
= 347 x ( 6 + 3 + 1 )
= 347 x 10
=3 470
b)
=2 013 x 3 + 2 013 x 7
=2 013 x ( 3 + 7 )
=2 013 x 10
=20 130
`Thảo`
2013.2+98.2013=2013.(98+2)=2013.100=201300