已知7^24-1可被40至50之間的兩個(gè)整數(shù)整除,這兩個(gè)整數(shù)是答案:43 48 求詳解
熱心網(wǎng)友
7^24-1=(7^12+1)(7^12-1)=(7^12+1)(7^6+1)(7^6-1)=(7^12+1)(7^6+1)(7^2-1)(7^4+7^2+1),7^2-1=48,即7^24-1是48的倍數(shù)又7^24-1=(7^12+1)(7^12-1)=(7^12+1)(7^6+1)(7^6-1)=(7^12+1)(7^6+1)(7^3+1)(7^3-1),7^3+1=(7+1)(7^2-7+1)=8*43,即7^24-1是43的倍數(shù)
熱心網(wǎng)友
7^24-1=(7^12+1)(7^12-1)=(7^12+1)(7^6+1)(7^6-1)=(7^12+1)(7^6+1)(7^3+1)(7^3-1)=(7^12+1)(7^6+1)*344*(7^3-1)=(7^12+1)(7^6+1)*43*8*(7^3-1)7^24-1=(7^8-1)(7^16+7^8+1)=(7^4+1)(7^4-1)(7^16+7^8+1)=(7^4+1)(7^2+1)(7^2-1)(7^16+7^8+1)=(7^4+1)*50*48*(7^16+7^8+1)
熱心網(wǎng)友
7^24-1=(7^12)^2-1=(7^12+1)(7^12-1)=(7^12+1)(7^6+1)(7^6-1)=(7^12+1)(7^6+1)(7^3+1)(7^3-1)=(7^12+1)(7^6+1)[(7+1)(7^2-7*1+1)][(7-1)(7^2+7*1+1)]=(7^12+1)(7^6+1)*48*43*57.∴7^24-1可被40至50之間的兩個(gè)整數(shù)整除,這兩個(gè)整數(shù)就是43,48.