展開
- \( (a+2)(b-c)=\) \(ab-ac+2b-2c\)
- \( (x+2)(x-1)=\) \(x^2+x-2\)
- \( (2x-1)(3x+2)=\) \(6x^2+x-2\)
- \( (2x+y)(y+x)=\) \(2x^2+3xy+y^2\)
- \( (x-2)^2=\) \(x^2-4x+4\)
- \( (2a+3b)^2=\) \(4a^2+12ab+9b^2\)
- \( (a-b-c)^2=\) \(a^2+b^2+c^2-2ab+2bc-2ca\)
- \( (2a+1)^3=\) \(8a^3+12a^2+6a+1\)
- \( (2-y)^3=\) \(-y^3+6y^2-12y+8\)
- \( (2-x)(4+2x+x^2)=\) \(-x^3+8\)
- \( (x+1)^4=\) \(x^4+4x^3+6x^2+4x+1\)
因数分解
- \(6a^2b^2-9ab^3= \) \(3ab^2(2a-3b)\)
- \(x^2-2x+1= \) \((x-1)^2\)
- \(2x^2+4xy+2y^2= \) \(2(x+y)^2\)
- \(a^2-a-6= \) \((a+2)(a-3)\)
- \(2x^2-x-1= \) \((2x+1)(x-1)\)
- \(1-4y^2= \) \((1+2y)(1-2y)\)
- \(2x^2+5xy+2y^2-2x-2y+1= \) \((2x+y-1)(x+2y-1)\)
- \(x^3-1= \) \((x-1)(x^2+x+1)\)
- \(x^3+x^2y-x-y= \) \((x+y)(x+1)(x-1)\)
- \(x^4-y^4= \) \((x^2+y^2)(x+y)(x-y)\)
- \(x^6-1= \) \((x^2+x+1)(x^2-x+1)(x+1)(x-1)\)
- \(x^4-5x^2+4= \) \((x+1)(x-1)(x+2)(x-2)\)
- \(x^4-7x^2+9= \) \((x^2+x-3)(x^2-x-3)\)
- \(x^3+y^3+z^3-3xyz= \) \((x+y+z)(x^2+y^2+z^2-xy-yz-zx)\)