ページ3:

1章2節 因数分解 教科書節末問題 自学@Akagi
1 【共通因数のくくり出し】
(1) Sax-25bx
= 5x(a – 5b)
-
(3) Axy ² -2xy
=
= 2xy(2y −1)
2 【公式1'~4'】
(1) x²+3x+2
= (x + 1)(x+2)
2
(3) x² -x-12
= (x-4)(x+3)
(5) 2-12x+36
= (x − 6) (x-6)
=(x-6)²
(2) 3x² y + xy
= xy(3x+1)
(4) a²b+2ab²
= ab(a + 2b)
(2) x²-6x+8
= (x-2)(x-4)
A x²+16x+64
= (x+4)(x+4)
???
=(x+4)² (x+8) 2
(6) x²-144
= (x+12)(x −12)

ページ4:

3 【公式(虫食い)】
(1)
2+2x-8
=(x-2)(x+ 4 4)
44 【いろいろな式の因数分解】
(1) Bx2
(1) Bx²-15x-18
=
= 3(x -5x−6)
=3(x+1)(x-6)
2
(3) ax² - ay²
= a(x² - y²)
= a(x + y)(x − y)
(2) x²-16x+ 64
=(x-8)2
(2)
- 4ab+4b²
-
= (a − 2b)(a – 2b)
= (a-2b)²
(4) 4x²+16xy+16y²
= 4(x² + 4xy+4y²)
=4(x+2y)²

ページ5:

5 【いろいろな式の因数分解】
(1) (x-2)² -6(x-2)+5 = A² -6A+5
(2) ab-a+(b−1)
6 式の値
= (x + y)(x − y)
= (85+15)(85-15)
= 100 × 70
= 7000
= (A-1)(A−5)
= (x-2-1)(x-2-5)
-
= (x − 3)(x − 7)
-
= (ab − a) + (b −1)
-
= (b−1)a + (b −1)
= (b−1)(a+1)
2
2
(2) x² + 2xy + y²
= (x + y)²
=
= (85+15)2
=1002
=10000
1間まちがえ\(^o^)/