tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
các cậu giải cho tớ với.mai học rồi nhé ai trả lời tớ tick cho
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
Tim x
a,-2/3(x-1/4)=1/3(2x-1)
b,1/5.2^x +1/3.2^x+1=1/5.2^7 +1/3.2^8
tim x : 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)-1/1/2010
tim x biet:
( 1/2 +1/3+ 1/4+ 1/5+ 1/6 +1/7)x (2009 * x ) = 0.63* 0.12 - 2,1 * 0,036
tim STN x biet
a, 21 thuoc B(x-3)
b, 1-x thuoc U(17)
c, 2x+3 thuoc B(2x-1)
d, x+1 thuoc U(x mu 2+x+3)
e, 3x+1:11-2x
tim x biet -2/3 (x-1/4)=1/3( 2x -1)
Tính nhanh theo mẫu:
Mẫu: \(B=\left(1+\dfrac{1}{3}\right)\)x \(\left(1+\dfrac{1}{8}\right)\)x \(\left(1+\dfrac{1}{15}\right)\)x \(\left(1+\dfrac{1}{24}\right)\)x ..... x \(\left(1+\dfrac{1}{120}\right)\)x \(\left(1+\dfrac{1}{413}\right)\)
\(B=\left(\dfrac{3}{3}+\dfrac{1}{3}\right)\)x \(\left(\dfrac{8}{8}+\dfrac{1}{8}\right)\)x \(\left(\dfrac{15}{15}+\dfrac{1}{15}\right)\)x \(\left(\dfrac{24}{24}+\dfrac{1}{24}\right)\)x........x\(\left(\dfrac{120}{120}+\dfrac{1}{120}\right)\)x \(\left(\dfrac{143}{143}+\dfrac{1}{143}\right)\)
\(B=\dfrac{4}{3}\)x\(\dfrac{9}{8}\)x\(\dfrac{16}{15}\)x\(\dfrac{25}{24}\)x.......x\(\dfrac{121}{120}\)x \(\dfrac{144}{143}\)
\(B=\dfrac{2x2}{1x3}\)x\(\dfrac{3x3}{2x4}\)x\(\dfrac{4x4}{3x5}\)x\(\dfrac{5x5}{4x6}\)x.......x\(\dfrac{11x11}{10x12}\)x\(\dfrac{12x12}{13x11}\)
\(B=\dfrac{2x3x4x5x......x10x11x12}{1x2x3x......x10x11x12}\)x \(\dfrac{2x3x4x5x....x11x12}{3x4x5x6x......x12x13}\)
B= \(\dfrac{12}{1}\)x\(\dfrac{2}{13}\)
B=\(\dfrac{24}{13}\)
Câu hỏi:
\(B=\left(1+\dfrac{1}{8}\right)\)x\(\left(1+\dfrac{1}{15}\right)\)x\(\left(1+\dfrac{1}{24}\right)\)x..... x \(\left(1+\dfrac{1}{440}\right)\)x \(\left(1+\dfrac{1}{483}\right)\)
Bai 1.Tim x:
x-{x-[x-(-x+1)]}=1
Bai 2. Tinh:
1+(-2)+3+(-4)+..............+2015
giup minh voi!!!
