2003x2005+\(\frac{200}{2004}\)x2004+199

=2003x2005+\(\frac{200x2004}{2004}\)+199

=4016015+200+199

=4016414

\(\frac{\frac{1}{9}-\frac{5}{6}-4}{\frac{7}{12}-\frac{1}{36}-10}=\frac{36.\left(\frac{1}{9}-\frac{5}{6}-4\right)}{36.\left(\frac{7}{12}-\frac{1}{36}-10\right)}\)

                             \(=\frac{4-6.5-36.4}{3.7-1-36.10}\)

                               \(=\frac{4-30-144}{21-1-360}\)

                               \(=\frac{-26-144}{20-360}=\frac{-170}{-340}=\frac{1}{2}\)

\(\frac{\frac{4}{36}-\frac{30}{36}-\frac{144}{36}}{\frac{21}{36}-\frac{1}{36}-\frac{360}{36}}=\frac{\frac{-170}{36}}{\frac{-340}{36}}=\frac{-170}{36}:\frac{-340}{36}=\frac{-170}{36}.\frac{36}{-340}=\frac{-170}{-340}=\frac{1}{2}\)

Bấm máy tính là ra ^0^

\(A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}\)

=>  \(2A=1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\)

=>  \(2A-A=\left(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}\right)\)

=>  \(A=1-\frac{1}{32}=\frac{31}{32}\)

Bài 1 : Cách 1 : \(A=\left\{5;6;7\right\}\)

Cách 2 : \(A=\left\{x\in N|4< x\le7\right\}\)

Các ý còn lại bạn làm tương tự :>

abccgjjn lol

vggghkbgffffffffffffffffffffffffffffffffffffff

k

n

chung to rang so 444222 co the viet thanh h 2 so tu nhien lien tiep

1 + 2 + 3 + ... + 200 / 6 + 8 + 10 + ... + 34

= (1 + 200) × 200 : 2 / 2 × (3 + 4 + 5 + ... + 17)

= 201 × 100 / 2 × (3 + 17) × 15 : 2

= 201 x 100 / 20 × 15

= 67

444222

= 444 × 1000 + 222

= 111 × 4 × 1000 + 111 × 2

= 111 × 4000 + 111 × 2

= 111 × (4000 + 2)

= 111 × 4002

= 111 × 2 x 3 x 667

= 666 x 667

=> đpcm

Ủng hộ mk nha ^_-

áp dụng công thực tinh dãy số ta có

Tử = (200-1):1+1   .   (200+1): 2 = 200 . 201 : 2 =20100

Mẫu = (34 - 6):2+1    .   (34+6):2 = 15.40 :2 =300

=> \(\frac{20100}{300}=67\)

444222 = 666 . 667