展開-1(6問)
次の式を展開せよ。
(a+1)(b-1)
解答○ ×(a-2)(b+1)
解答○ ×(x-1)(y-3)
解答○ ×(x+4)(y+5)
解答○ ×(a+b)(x+y)
解答○ ×(a-b)(c-1)
解答○ ×問題と解答
(a+1)(b-1)ab-a+b-1 (a-2)(b+1)ab+a-2b-2 (x-1)(y-3)xy-3x-y+3 (x+4)(y+5)xy+5x+4y+20 (a+b)(x+y)ax+ay+bx+by (a-b)(c-1)ac-bc-a+b
(a+1)(b-1)ab-a+b-1 (a-2)(b+1)ab+a-2b-2 (x-1)(y-3)xy-3x-y+3 (x+4)(y+5)xy+5x+4y+20 (a+b)(x+y)ax+ay+bx+by (a-b)(c-1)ac-bc-a+b
