Ta có:
` A = 12^{37} - 12^{36} `
` <=> A = 12^{36} . 12 - 12^{36} `
` <=> A = 12^{36} . (12 - 1) `
` <=> A = 12^{36} . 11 `
` B = 12^{36} - 12^{35} `
` <=> B = 12^{35} . 12 - 12^{35} `
` <=> B = 12^{35} . (12 - 1) `
` <=> B = 12^{35} . 11 `
Do: ` 12^{36} > 12^{35} `
` <=> 12^{36} . 11 > 12^{35} . 11 `
` <=> A > B `
Vậy ` A > B `