251750

251742

\(\frac{2006\cdot125+1000}{126\cdot2005-888}=\frac{2005\cdot125+125+1000}{125\cdot2005+2005-888}=\frac{2005\cdot125+1125}{125\cdot2005+1117}\)

=> không tính nhanh được

dễ nha bạn ơi

2006.125 + 1000 / 126. 2005 - 880                                                                                                                                                                        = ( 2005 + 1 ). 125 + 1000 / (125+1). 2005 - 880                                                                                                                                                =2005. 125 + 125 + 1000 / 2005. 125 + 2005 -880                                                                                                                                            =2005. 125 = 1125 / 2005 + 125 + 1125

\(\frac{\text{2006 x 125 + 1000}}{\text{ 2005 x 126 - 880}}=???\)

Trả lời :

\(\frac{\text{2006 x 125 + 1000}}{\text{2005 x 126 - 880}}=\frac{\text{251750}}{\text{251750}}=1\)

Chúc bạn học tốt !

\(B=\frac{2006\cdot125+1000}{126\cdot2005-880}\)

= \(\frac{2005\cdot125+125+1000}{2005\cdot126-880}=\frac{2005\cdot125+1125}{2005\cdot126-880}\)

=\(\frac{2005\cdot125+1125}{2005\cdot125+125-880}=1,007523912\)

A = 2006 x 125 + 1000 / 126 x 2005 - 888

A = (2005 + 1) x 125 + 1000 / (125 + 1) x 2005 - 888

A = 2005 x 125 + 125 + 1000 / 125 x 2005 + 2005 - 888

A = 2005 x 125 + 1125 / 125 x 2005 + 1117

A = 1125 / 1117

Lahh dsr uẹđb bh s

\(\frac{\left(2005+1\right).125+1000}{\left(125+1\right).2005-888}\)

= \(\frac{2005.125+125+1000}{125.2005+2005-888}\)

= \(\frac{2005.125+1125}{125.2005+1117}\)

= \(\frac{250625+1125}{250625+1117}\)

= \(\frac{125875}{125871}\)

a, 2006 x 2004 - \(\frac{2}{1995}\) + 2004 x 2005 = 8038043,999

b, 2006 x 125 + \(\frac{1000}{126}\) x 2006 - 1006 = 265664,6349

c, A = 1991 x 1999

=> A = ( 1995 - 4 ) x ( 1995 + 4 )

     A = 1995 x ( 1995 + 4 ) - 4 x ( 1995 + 4 )

     A = 1995 x 1995 + 1995 x 4 - ( 4 x 1995 + 4 x 4 )

     A = 1995 x 1995 - 4 x 4

mà B = 1995 x 1995

Vậy A < B

d, Gọi giá trị biểu thức là C

C =  \(\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+\frac{1}{48}+\frac{1}{96}\) 

C x 2 = \(\frac{2}{3}+\frac{2}{6}+\frac{2}{12}+\frac{2}{24}+\frac{2}{48}+\frac{2}{96}\)

C x 2 = \(\frac{2}{3}+\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+\frac{1}{48}\)

Vậy C x 2 - C = \(\left(\frac{2}{3}+\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+\frac{1}{48}\right)-\left(\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+\frac{1}{48}+\frac{1}{96}\right)\)

                  C = \(\frac{2}{3}-\frac{1}{96}\) ( vì phân số nào có ở số bị trừ cũng có ở số trừ thì trừ hết rồi nên không còn )

                  C = \(\frac{21}{32}\)

A=1991x1999=(1995-4)1999=1995x1999-4x1999

B=1995x1995=1995x(1999-4)=1995x1999-1995x4>1995x1999-4x1999=A

vậy A<B

a, 5/3*4/7*3/5*7/8

= (5/3*3/5)*(4/7*7/8)

= 1*1/2

=1/2

b, 2006*125+1000/126*2005-880

= (2005+1)*125+1000/126*2005-880

=2005*125+125+1000/126*2005-880

=2005*(125+1000/126)-880+125

=2005*8375/63-880+125

=266537,6984-880+125

=265657,6984+125

=265782,6984

a,  ( 32,5 + 28,3 X 2,7 - 108,91 ) X 2006
= (32,5 + 76,41 - 108,91)X 2006
= (108,91 - 108,91) X 2006
= 0 X 2006
= 0

b, \(\frac{2006.125+1000}{126.2005-880}=\frac{2005.125+125+1000}{125.2005+2005-880}=\frac{2005.125+1125}{125.2005+1125}=1\)