\(\dfrac{23}{6}\times\dfrac{5}{3}=\dfrac{23\times5}{6\times3}=\dfrac{115}{18}\)

23/6×5/3

= 23 x 5/ 6 x 3

= 115 /18

\(\dfrac{3}{2}+\dfrac{7}{3}=\dfrac{3.3}{2.3}+\dfrac{7.2}{3.2}\\ =\dfrac{9}{6}+\dfrac{14}{6}=\dfrac{9+14}{6}\\ =\dfrac{23}{6}\)

3/2+7/3 ( quy đồng lên mẫu số chung là 6)

= 9/6 + 14/6

= 9+14/6

= 23/6 

2/3×5/7+5/7×2/3+2/3×3/7

= 2/3 x ( 5/7 + 5/7 + 3/7)

= 2/3 x 13/7

= 2x13/3x7

= 26/21

2/3×5/7+5/7×2/3+2/3×3/7 

5/7 x ( 2/3+2/3+2/3)

5/7 x 6/3

30/21

Quy đồng MSC : 6

Làm từ trái qua phải nha 

MSC : mẫu số chung nha 

\(\left(a\right):\left(2x-6\right)^3=0=>2x-6=0=>2x=6=>x=3\)

\(\left(b\right):7⋮\left(x+1\right)=>x+1\inƯ\left(7\right)=\left\{\pm1;\pm7\right\}\\ =>x\in\left\{0;6;-2;-8\right\}\)

\(\left(c\right):x⋮12=>x\in B\left(12\right)=\left\{0;12;24;36;48;60;....\right\}\\ 40< x< 50=>x=48\)

gọi tập hợp đó là A, ta được:

A = { 100: 102:.........;198}

Nêu cách làm (3/8)+(1/4)+2 nha 

(3/8)+(1/4)+2=3/8+2/8+16/8=21/8

101/506=101.7/506.7=707/3542

707/3542<707/3534

=>101/506<707/3534

Lời giải:

a.

$2^3.225.45=2^3.15^2.3^2.5=2^3.5^2.3^2.3^2.5$

$=2^3.3^4.5^3$

b.

$5.10.15.20=5.5.2.5.3.5.4=2.3.4.5^4=2.3.2^2.5^4=2^3.3.5^4$