Question

分解因式；x^2(a-1)+4(1-a); (a+b)(a-b)-5(a^2-2b^2)

Answer 1

x^2(a-1)+4(1-a)
=x^2(a-1)-4(a-1)
=(x²-4)(a-1)
=(x+2)(x-2)(a-1)

(a+b)(a-b)-5(a^2-2b^2)
=a²-b²-5a²+10b²
=9b²-4a²
=(3b+2a)(3b-2a)

Answer 2

x^2(a-1)+4(1-a)
＝x^2(a-1)-4(a-1)
=(a-1)(x^2-4)
=(a-1)(x+2)(x-2)

(a+b)(a-b)-5(a^2-2b^2)
=a^2-b^2-5a^2+10b^2
=9b^2-4a^2
=(3b+2a)(3b-2a)