해법
확장 (x2+2x)15
해법
x30+30x57+420x27+3640x51+21840x24+96096x45+320320x21+823680x39+1647360x18+2562560x33+3075072x15+2795520x27+1863680x12+860160x21+245760x9+32768x15
솔루션 단계
(x2+2x)15
이항 정리 적용: (a+b)n=i=0∑n(in)a(n−i)bia=x2,b=2x
=i=0∑15(i15)(x2)(15−i)(2x)i
합계 확장
=0!(15−0)!15!(x2)15(2x)0+1!(15−1)!15!(x2)14(2x)1+2!(15−2)!15!(x2)13(2x)2+3!(15−3)!15!(x2)12(2x)3+4!(15−4)!15!(x2)11(2x)4+5!(15−5)!15!(x2)10(2x)5+6!(15−6)!15!(x2)9(2x)6+7!(15−7)!15!(x2)8(2x)7+8!(15−8)!15!(x2)7(2x)8+9!(15−9)!15!(x2)6(2x)9+10!(15−10)!15!(x2)5(2x)10+11!(15−11)!15!(x2)4(2x)11+12!(15−12)!15!(x2)3(2x)12+13!(15−13)!15!(x2)2(2x)13+14!(15−14)!15!(x2)1(2x)14+15!(15−15)!15!(x2)0(2x)15
0!(15−0)!15!(x2)15(2x)0간소화하다 :x30
1!(15−1)!15!(x2)14(2x)1간소화하다 :30x28x
2!(15−2)!15!(x2)13(2x)2간소화하다 :420x27
3!(15−3)!15!(x2)12(2x)3간소화하다 :3640x24(x)3
4!(15−4)!15!(x2)11(2x)4간소화하다 :21840x24
5!(15−5)!15!(x2)10(2x)5간소화하다 :96096x20(x)5
6!(15−6)!15!(x2)9(2x)6간소화하다 :320320x21
7!(15−7)!15!(x2)8(2x)7간소화하다 :823680x16(x)7
8!(15−8)!15!(x2)7(2x)8간소화하다 :1647360x18
9!(15−9)!15!(x2)6(2x)9간소화하다 :2562560x12(x)9
10!(15−10)!15!(x2)5(2x)10간소화하다 :3075072x15
11!(15−11)!15!(x2)4(2x)11간소화하다 :2795520x8(x)11
12!(15−12)!15!(x2)3(2x)12간소화하다 :1863680x12
13!(15−13)!15!(x2)2(2x)13간소화하다 :860160x4(x)13
14!(15−14)!15!(x2)1(2x)14간소화하다 :245760x9
15!(15−15)!15!(x2)0(2x)15간소화하다 :32768(x)15
=x30+30x28x+420x27+3640x24(x)3+21840x24+96096x20(x)5+320320x21+823680x16(x)7+1647360x18+2562560x12(x)9+3075072x15+2795520x8(x)11+1863680x12+860160x4(x)13+245760x9+32768(x)15
x30+30x28x+420x27+3640x24(x)3+21840x24+96096x20(x)5+320320x21+823680x16(x)7+1647360x18+2562560x12(x)9+3075072x15+2795520x8(x)11+1863680x12+860160x4(x)13+245760x9+32768(x)15간소화하다 :x30+30x257+420x27+3640x251+21840x24+96096x245+320320x21+823680x239+1647360x18+2562560x233+3075072x15+2795520x227+1863680x12+860160x221+245760x9+32768x215
=x30+30x257+420x27+3640x251+21840x24+96096x245+320320x21+823680x239+1647360x18+2562560x233+3075072x15+2795520x227+1863680x12+860160x221+245760x9+32768x215
x30+30x257+420x27+3640x251+21840x24+96096x245+320320x21+823680x239+1647360x18+2562560x233+3075072x15+2795520x227+1863680x12+860160x221+245760x9+32768x215간소화하다 :x30+30x57+420x27+3640x51+21840x24+96096x45+320320x21+823680x39+1647360x18+2562560x33+3075072x15+2795520x27+1863680x12+860160x21+245760x9+32768x15
=x30+30x57+420x27+3640x51+21840x24+96096x45+320320x21+823680x39+1647360x18+2562560x33+3075072x15+2795520x27+1863680x12+860160x21+245760x9+32768x15