1254600

16875 KO PHẢI ĐÂU CÁC BẠN

ok uy tín UnU

tử số : 8,1/0,6*1875+1,5*6,25*9=13,5*1875+13,5*6,25=13,5*/(1875+6,25)=13,5*1881,25=25396,875

mẫu số : 105+205+795+895=1(105+895)+(205+795)=1000+1000=2000

25396,875/2000=12,6984375

đs (theo máy tính)

ra 16.875 mk đúng đó

X x 4 = 32                                                                                           

      x = 32 : 4

      x = 8

42 : y = 7

       y = 42 : 7

       y = 6

Vậy tỉ số giữa x và y là \(\frac{8}{6}\)

6120 * 205 = 1254600

= 1254600

là sao

Ta có: \(\frac{1}{201\times299}+\frac{1}{203\times297}+\cdots+\frac{1}{297\times203}+\frac{1}{299\times201}\)

\(=\frac{2}{201\times299}+\frac{2}{203\times297}+\cdots+\frac{2}{249\times251}\)

\(=\frac{2}{500}\times\left(\frac{500}{201\times299}+\frac{500}{203\times297}+\cdots+\frac{500}{249\times251}\right)\)

\(=\frac{1}{250}\times\left(\frac{1}{201}+\frac{1}{299}+\frac{1}{203}+\frac{1}{297}+\cdots+\frac{1}{249}+\frac{1}{251}\right)\)

\(=\frac{1}{250}\times\left(\frac{1}{201}+\frac{1}{203}+\cdots+\frac{1}{297}+\frac{1}{299}\right)\)

Ta có: \(\frac{\left(\frac{1}{201}+\frac{1}{203}+\cdots+\frac{1}{297}+\frac{1}{299}\right)}{\frac{1}{201\times299}+\frac{1}{203\times297}+\cdots+\frac{1}{297\times203}+\frac{1}{299\times201}}\)

\(=\frac{\left(\frac{1}{201}+\frac{1}{203}+\cdots+\frac{1}{297}+\frac{1}{299}\right)}{\frac{1}{250}\times\left(\left(\frac{1}{201}+\frac{1}{203}+\cdots+\frac{1}{297}+\frac{1}{299}\right)\right)}\)

\(=1:\frac{1}{250}=250\)

bài 1

a,

32 + 68 :17 x 5 - 29

= 32 + 20 -29

= 52 - 29

= 23

b,

15 x 48 - 30 x 24 - 125

= 720 - 720 -125

= 0-125

a,

32 + 68 :17 x 5 - 29

= 32 + 20 -29

= 52 - 29

= 23

b,

15 x 48 - 30 x 24 - 125

= 720 - 720 -125

= 0-125

\(B-A=5,75\times2009-4,75\times2009\)

\(B-A=\text{​​}\text{​​}2009\times\left(5,75-4,75\right)=2009\times1\)

\(=2009\)

\(B-A=5,75\times2009-2009\times4,75\text{ }\)

\(B-A=\left(5,75-4,75\right)\times2009\)

\(B-A=1\times2009\)

\(B-A=2009\)