Question

Rút gọn biểu thức

(a+b).(c+d)-(a+d).(b+c)

Answer 1

(a+b).(c+d)-(a+d).(b+c)

=(-c-b).d+b.c+b^2

Answer 2

(a+b).(c+d)-(a+d).(b+c)

=ac+ad+bc+bd-ab-ac-bd-dc

=(ac-ac)+(bd-bd)+(ad-ab)+(bc-dc)

=0+0+a.(d-b)+c.(b-d)

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

Hok tốt

Answer 3

\(\left(a+b\right)\left(c+d\right)-\left(a+d\right)\left(b+c\right)\)

\(=ac+ad+bc+bd-ab-ac-db-dc\)

\(=ad+bc-ab-dc\)

\(=\left(ad-ab\right)+\left(bc-dc\right)\)

\(=a\left(d-b\right)+c\left(b-d\right)\)

\(=a\left(d-b\right)-c\left(d-b\right)\)

\(=\left(a-c\right)\left(d-b\right)\)