해법
확장 (x+x2+1)10
해법
512x10+10x9x2+1+1280x8+120x7x2+1(x2+1)+1120x6+252x5(x2+1)2x2+1+400x4+120x3(x2+1)3x2+1+50x2+10x(x2+1)4x2+1+1
솔루션 단계
(x+x2+1)10
이항 정리 적용: (a+b)n=i=0∑n(in)a(n−i)bia=x,b=x2+1
=i=0∑10(i10)x(10−i)(x2+1)i
합계 확장
=0!(10−0)!10!x10(x2+1)0+1!(10−1)!10!x9(x2+1)1+2!(10−2)!10!x8(x2+1)2+3!(10−3)!10!x7(x2+1)3+4!(10−4)!10!x6(x2+1)4+5!(10−5)!10!x5(x2+1)5+6!(10−6)!10!x4(x2+1)6+7!(10−7)!10!x3(x2+1)7+8!(10−8)!10!x2(x2+1)8+9!(10−9)!10!x1(x2+1)9+10!(10−10)!10!x0(x2+1)10
0!(10−0)!10!x10(x2+1)0간소화하다 :x10
1!(10−1)!10!x9(x2+1)1간소화하다 :10x9x2+1
2!(10−2)!10!x8(x2+1)2간소화하다 :45x8(x2+1)
3!(10−3)!10!x7(x2+1)3간소화하다 :120x7(x2+1)3
4!(10−4)!10!x6(x2+1)4간소화하다 :210x6(x2+1)2
5!(10−5)!10!x5(x2+1)5간소화하다 :252x5(x2+1)5
6!(10−6)!10!x4(x2+1)6간소화하다 :210x4(x2+1)3
7!(10−7)!10!x3(x2+1)7간소화하다 :120x3(x2+1)7
8!(10−8)!10!x2(x2+1)8간소화하다 :45x2(x2+1)4
9!(10−9)!10!x1(x2+1)9간소화하다 :10x(x2+1)9
10!(10−10)!10!x0(x2+1)10간소화하다 :(x2+1)5
=x10+10x9x2+1+45x8(x2+1)+120x7(x2+1)3+210x6(x2+1)2+252x5(x2+1)5+210x4(x2+1)3+120x3(x2+1)7+45x2(x2+1)4+10x(x2+1)9+(x2+1)5
45x8(x2+1) 확장 :45x10+45x8
=x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x6(x2+1)2+252x5(x2+1)5+210x4(x2+1)3+120x3(x2+1)7+45x2(x2+1)4+10x(x2+1)9+(x2+1)5
210x6(x2+1)2 확장 :210x10+420x8+210x6
=x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x10+420x8+210x6+252x5(x2+1)5+210x4(x2+1)3+120x3(x2+1)7+45x2(x2+1)4+10x(x2+1)9+(x2+1)5
210x4(x2+1)3 확장 :210x10+630x8+630x6+210x4
=x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x10+420x8+210x6+252x5(x2+1)5+210x10+630x8+630x6+210x4+120x3(x2+1)7+45x2(x2+1)4+10x(x2+1)9+(x2+1)5
45x2(x2+1)4 확장 :45x10+180x8+270x6+180x4+45x2
=x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x10+420x8+210x6+252x5(x2+1)5+210x10+630x8+630x6+210x4+120x3(x2+1)7+45x10+180x8+270x6+180x4+45x2+10x(x2+1)9+(x2+1)5
(x2+1)5 확장 :x10+5x8+10x6+10x4+5x2+1
=x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x10+420x8+210x6+252x5(x2+1)5+210x10+630x8+630x6+210x4+120x3(x2+1)7+45x10+180x8+270x6+180x4+45x2+10x(x2+1)9+x10+5x8+10x6+10x4+5x2+1
x10+10x9x2+1+45x10+45x8+120x7(x2+1)3+210x10+420x8+210x6+252x5(x2+1)5+210x10+630x8+630x6+210x4+120x3(x2+1)7+45x10+180x8+270x6+180x4+45x2+10x(x2+1)9+x10+5x8+10x6+10x4+5x2+1간소화하다 :512x10+10x9x2+1+1280x8+120x7x2+1(x2+1)+1120x6+252x5(x2+1)2x2+1+400x4+120x3(x2+1)3x2+1+50x2+10x(x2+1)4x2+1+1
=512x10+10x9x2+1+1280x8+120x7x2+1(x2+1)+1120x6+252x5(x2+1)2x2+1+400x4+120x3(x2+1)3x2+1+50x2+10x(x2+1)4x2+1+1