第1章 1.12

(1)

x2+7x+12=(x+3)(x+4)x^2 + 7x + 12 = (x+3)(x+4)

(2)

x220x+36=(x18)(x2)x^2 - 20x + 36 = (x-18)(x-2)

(3)

3p213p10=(3p+2)(p5)3p^2 - 13p - 10 = (3p+2)(p-5)

(4)

12a2+5a2=(4a1)(3a+2)12a^2 + 5a - 2 = (4a-1)(3a+2)

(5)

6t27t3=(3t+1)(2t3)6t^2 - 7t - 3 = (3t+1)(2t-3)

(6)

12a2+21a+9=3(4a2+7a+3)=3(4a+3)(a+1)12a^2 + 21a + 9 = 3(4a^2 + 7a + 3) = 3(4a+3)(a+1)

解説: r31bn1z