=2.3+(2.3).4+(2.3).49

3.5+(3.5).4+(3.5).49

=2.3.(1+4+49)

3.5.(1+4+49)

=2.3

3.5

=6

15

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}=\frac{2.\left(3+2.6+7.21\right)}{5.\left(3+2.6+7.21\right)}=\frac{2}{5}\)

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}=\frac{2.\left(3+2.6+7.21\right)}{5.\left(3+2.6+7.21\right)}=\frac{2}{5}\)

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}=\frac{2.3+8.3+98.3}{3.5+3.20+3.45}=\frac{3.\left(2+8+98\right)}{3.\left(5+20+45\right)}=\frac{108}{70}=\frac{54}{35}=1\frac{19}{35}\)

rút gọn PS

3.7.13.37.39-10101/505050-70707

làm bài dưới :

rút gọn phân số : 

\(\frac{3.7.13.37.39-10101}{505050-70707}\)

\(=\frac{10101.39-10101}{50.10101-7.10101}\)

\(=\frac{10101.\left(39-1\right)}{10101.\left(50-7\right)}\)

\(=\frac{38}{43}\)

2.3+4.6+14.21/3.5+6.10+21.35

= 2 . 3 + 2 . 2 . 3 . 2 + 7 .

\(\frac{2\cdot3+4\cdot6+14\cdot21}{3\cdot5+6\cdot10+21\cdot35}\)=\(\frac{2\cdot3\cdot\left(1+2\cdot2+7\cdot7\right)}{3\cdot5\cdot\left(1+2\cdot2+7\cdot7\right)}\)

Sau đó ta chia tử và mẫu cho (1+2*2+7*7) thì ta có phân số

\(\frac{2\cdot3}{3\cdot5}\)=\(\frac{2}{5}\)(rút gọn tử và mẫu cho 3)

..............

2.3 + 4.6 + 14.21 / 3.5 + 6.10 + 21.35

= 2.3.(1 + 2.2 + 7.7) / 3.5.(1 + 2.2 + 7.7)

= 2/5

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}=\frac{2.3+4.6+2.7.3.7}{3.5+2.3.5.2+3.7.5.7}\)

\(=\frac{6.1+4.6+6.49}{15.1+15.4+15.49}\)

\(=\frac{6\left(1+4+49\right)}{35\left(1+4+49\right)}=\frac{6}{35}\)

tren tu : dat 2.3 ra ngoai

trong ngoặc: 1+2.2+7.7

dưới mẫu : dat 3.5 ra ngoai

trong ngoặc: 1+2.2+7.7

rút gọn: 2.3/3.5=2/5

cho mk vs

\(\dfrac{2\cdot3+4\cdot6+14\cdot21}{3\cdot5+6\cdot10+21\cdot35}=\dfrac{2\left(3+2\cdot3+7\cdot21\right)}{3\left(5+2\cdot10+7\cdot35\right)}=\dfrac{2\cdot3\left(1+2\cdot3+7\cdot5\right)}{3\cdot5\left(1+2\cdot3+7\cdot5\right)}=\dfrac{2}{5}\)

\(\dfrac{2.3+4.6+14.21}{3.5+6.10+21.35}\)

\(=\dfrac{6+24+294}{15+60+735}\)

\(=\dfrac{324}{810}\)

\(=\dfrac{2}{5}\)

\(\dfrac{2.3+4.6+14.21}{3.5+6.10+21.35}=\dfrac{2.3+\left(2.3\right).2^2+\left(2.3\right).7^2}{3.5+\left(3.5\right).2^2+\left(3.5\right).7^2}\\ \\ \\ \\ =\dfrac{2.3.\left(1+2^2+7^2\right)}{3.5.\left(1+2^2+7^2\right)}\\ \\ \\ \\ =\dfrac{2.3}{3.5}=\dfrac{2}{5}\)

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}\)

=\(\frac{2\left(3+2.6+7.21\right)}{5\left(3+2.6+7.21\right)}\)

=\(\frac{2}{5}\)

ta có:

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}\)

bài trên có các số ở tử và mẫu giống nhau đó là: 21;6;3

=>ta cho chúng hết cho nhau

vậy ta còn phân số:

\(\frac{2+4+14}{3+10+35}\)

=\(\frac{20}{48}\)=\(\frac{5}{12}\)

\(\frac{2.3+4.6+14.21}{3.5+6.10+21.35}=\frac{2+4+14}{5+10+35}=\frac{20}{40}=\frac{1}{2}\)Tự tính