\(\dfrac{\overline{abcdabcd}}{\overline{ghikghik}}\)
Ta có :
\(\overline{abcdabcd}=10.000.000a+1.000.000b+100.000c+10.000d+1.000a+100b+10c+d\)
\(=10.001.000a+1.000.100b+100.010c+10.001d\)
\(=10.001\left(1000a+100b+10c+d\right)\)
Lại có :
\(\overline{ghikghik}=10.000.000g+1.000.000h+100.000i+10.000k+1.000g+100h+10i+k\)
\(=10.001.000g+1.000.100h+100.010i+10.001k\)
\(=10.001\left(1000g+100h+10i+k\right)\)
Thay lại vào số ban đầu :
\(\dfrac{10.001\left(1000a+100b+10c+d\right)}{10.001\left(1000g+100h+10i+k\right)}=\dfrac{1000a+100b+10c+d}{1000g+100h+10i+k}=\dfrac{\overline{abcd}}{\overline{ghik}}\)
4 và 5