Question

PTĐTTNT

ab(a+b)-bc(b+c)+ac(a-c)+2abc

Answer 1

ab(a+b)-bc(b+c)+ac(a-c)+2abc = [ab(a+b)+abc]-[bc(b+c)+abc]+ac(a-c)

=ab(a+b+c)-bc(a+b+c)+ac(a-c)

=(ab-bc)(a+b+c)+ac(a-c)

=b(a-c)(a+b+c)+ac(a-c)

=(a-c)[b(a+b+c)+ac] = (a-c)(ab+bc+ac+b²)

Answer 2

mk sửa thêm nha :

(a-c)(ab+bc+ac+b²) = (a-c)[(ab+ac)+(bc+b²)] = (a-c)[a(b+c)+b(b+c)]

= (a-c)(a+b)(b+c)