bài tập toán

Question

Phân tích tử và mẫu thành nhân tử rồi rút gọn phân thức:

a)3x2−12x+12x4−8x

b)7x2+14x+73x2+3x

Answer 1

a)3x2−12x+12x4−8x=3(x2−4x+4)x(x3−8)=3(x−2)2x(x3−23)3x2−12x+12x4−8x=3(x2−4x+4)x(x3−8)=3(x−2)2x(x3−23)

=3(x−2)2x(x−2)(x2+2x+4)=3(x−2)x(x2+2x+4)=3(x−2)2x(x−2)(x2+2x+4)=3(x−2)x(x2+2x+4)

b)7x2+14x+73x2+3x=7(x2+2x+1)3x(x+1)=7(x+1)23x(x+1)7x2+14x+73x2+3x=7(x2+2x+1)3x(x+1)=7(x+1)23x(x+1)=7(x+1)3x=7(x+1)3x