câu 1:
a,A=(8ab-6a^2)/(9ab-12b^2)=2a(4b-3a)/3b(3a-4b)=2a(4b-3a)/-3b(4b-3a)=2a/-3b
b,B=(a^3-27)/(a^2-9)=(a-3)(a^2+3a+9)/(a-3)(a+3)=(a^2+3a+9)/(a+3)
câu 2:
ta có :
x^2-4x+4=(x-2)^2
3x-6=3(x-2)
x^2-5x+6=(x-2)(x-3)
MTC: 3(x-2)^2(x-3)
2x/(x^2-4x+4)=2x/(x-2)^2=6x(x-3)/3(x-2)^2(x-3)
4/(3x-6)=4/3(x-2)=4(x-2)(x-3)/3(x-2)^2(x-3)
(x-1)/(x^2-5x+6)=(x-1)/(x-2)(x-3)=3(x-2)(x-1)/ 3(x-2)^2(x-3)
