2016*97+2016*2+2016
2016 * 97 + 2016 * 2016 *2
8324064 nha bạn
Nhớ k cho mình nha
Chúc các bạn học giỏi
2016*97+2016*2016+2=(2016*97)+(2016*2016*2)
=195552+8128512
=8324064
k minh nhe ban
1.Tính:
a, B=1/2016+13/2016+15/2016+37/2016+..........+97/2016
b, C=3/2+3/4+3/8+3/16+3/32+3/64+3/128+3/256
2. Cho A=1/5x5+1/6x6+1/7x7+........+1/100x100.Chứng tỏ rằng 1/6<A<1/4
khẩn cấp nhé các bạn, mình cần giải ngay
dấu / là dấu trong phân số đấy các bạn
\(A< \frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+....+\frac{1}{99.100}\)
\(A< \frac{1}{4}-\frac{1}{100}\)
\(A< \frac{6}{25}< \frac{1}{4}\)
Bài 1 :
a, - { -(2016 +2015) - [ - (2016 - 2015) - (2016+2015) ] }
b, 2016 - { ( 2016 + 3) - [ (2016 + 3) - (- 2016 - 2) ] }
c, [ 2016 + (2016 + 3) ] - [ (2016 + 2) - (2016 - 2) ]
a, - { -(2016 +2015) - [ - (2016 - 2015) - (2016+2015) ] }
= -{-(2016+2015)-[-0-0]}
= -{-4031-0-0}
=-4031
cho x^2/a^2 + y^2/b^2 + z^2/c^2 =x^2+y^2+z^2/a^2+b^2+c^2
CMR x^2016/a^2016 + y^2016/b^2016 +z^2016/c^2016 = x^2016+y^2016+z^2016/a^2016+b^2016+c^2016
tinh nhanh: 1^2016+2^2016+3^2016+.......+10^2016/2^2016+4^2016+6^2016+.....+20^2016
\(2^{2016}+4^{2016}+6^{2016}+...+20^{2016}=2^{2016}\left(1+2^{2016}+3^{2016}+...+10^{2016}\right)\)
Do đó:
\(A=\frac{1^{2016}+2^{2016}+3^{2016}+...+10^{2016}}{2^{2016}+4^{2016}+6^{2016}+...+20^{2016}}=\frac{1}{2^{2016}}\)
Cho A=2016^2016+2/2016^2016-1 và B=2016^2016/2016^2016-3
Ta có:A=\(\frac{2016^{2016}+2}{2016^{2016}-1}\)>1
=>A<\(\frac{2016^{2016}+2-2}{2016^{2016}-1-2}\)=\(\frac{2016^{2016}}{2016^{2016}-3}\)=B
=>A<B(công thức nếu \(\frac{a}{b}\)>1 thì \(\frac{a}{b}\)<\(\frac{a-n}{b-n}\)(nEN)
CM công thức:
Ta có \(\frac{a}{b}\)>1=>a>b=>a=b+n(nEN)
Ta so sánh \(\frac{a}{b}\) và \(\frac{a-n}{b-n}\)(nEN)
Mà a*(b-n)=ab-an=ab-(b+n)*n=ab-(bn+n2)=ab-bn-n2
b*(a-n)=ba-bn
Vì ab-bn-n2<ba-bn
=>\(\frac{a}{b}\)<\(\frac{a-n}{b-n}\)
Rút gọn A= 1^2016+2^2016+3^2016+....+10^2016/ 2^2016+3^2016+....+20^2016
So Sánh A=2016^2016+2/2016^2016-1 và B=2016^2016/2016^2016-3
(1/2+2015/2016+2016/2017+1)(2015/2016+2016/2017+7/22)-(1/2+2015/2016+2016/2017)(2015/2016+2016/2017+7/22+1)