因式分解,急~~~
发布网友
发布时间:2024-10-18 17:54
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共3个回答
热心网友
时间:2024-10-18 18:08
1) x^3+3x^2+3x-7=(x^3-x^2)+4(x^2-x)+7(x-1)
=x^2(x-1)+4x(x-1)+7(x-1)
=(x-1)(x^2+4x+7)
2)x^3+x-2=(x^3-x^2)+(x^2-x)+(2x-2)
=x^2(x-1)+x(x-1)+2(x-1)
=(x-1)(x^2+x+2)
3)1^2-2^2+3^2-4^2+...+99^2-100^2
=(1+2)(1-2)+(3+4)(3-4)+....+(99+100)(99-100)
=-(1+2+3+4+....+100)
=-(1+100)*100/2
=-5050
4)(2^2+1)(2^4+1)(2^8+1)....(2^32+1)
=1/3*(2^2-1)(2^2+1)(2^4+1)(2^8+1)....(2^32+1)
=1/3*(2^4-1)(2^4+1)...(2^32+1)
=...
=1/3*(2^32-1)(2^32+1)
=1/3*(2^64-1)
热心网友
时间:2024-10-18 18:05
1.(x-1)(x^2+4x+7)
2.(x-1)(x^2+x+2)
3.前后两项进行平方差
4.前面配一个(2-1)反复使用平方差公式
热心网友
时间:2024-10-18 18:11
唉....小生不才,只能给你解2:x³+3x²+3x-7
=x(x²+1)-2
=x(x²-1+2)+2
=x[(x+1)(x-1)+2]+2
=x(x+1)(x-1)+2x+2
=x(x+1)(x-1)+2(x+1)
=(x+1)[x(x-1)+2]
3:1-2²+3²-4²+5².......+99²-100²
=(1-2²)+(3²-4²)+(5².......+(99²-100²)
=(1-2)(1+2)+(3-4)(3+4)+.......(99-100)(99+100)
=-(1+2)-(3+4)-(5+6).......-(99+100)
=-1-2-3-4-5-6.....-99-100
=-5050
4:(2²-1)(2²+1)(2 4+1)(2 8+1)(2 16+1)(2 32+1)÷(2²-1)
=(2 4-1)(2 4+1)(2 8+1)(2 16+1)(2 32+1)÷(2²-1)
=(2 8-1)(2 8+1)(2 16+1)(2 32+1)÷(2²-1)
=(2 16-1)(2 16+1)(2 32+1)÷(2²-1)
=(2 16-1)(2 16+1)(2 32+1)÷(2²-1)
=(2 32-1)(2 32+1)÷(2²-1)
=(2 64-1)÷ (2²-1)
=(2 64-1)/3