a) ab - ac + ad

= a(b - c + d)

b) ac + ad - bc - bd

= a(c + d) -  b(c - d)

= a - b

a) ab -ac+ad

=a+(b-c+d)

b)ac+ad-bc-bd

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

a) ab - ac + ad = a(b - c + d)

b) ac + ad - bc - bd = a(c + d) - b(c + d) = (a - b) (c + d)

a) Ta có \(ab-ac+ad=a.\left(b-c+d\right)\)

b) Ta có \(ac+ad-bc-bd=a.\left(c+d\right)-b.\left(c+d\right)\)

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

a) ab - ac + ad

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

= a.(b-c+d)

b) ac + ad - bc - bd

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

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

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

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

a, ab - ac + ad

= a . b - a . c - a . d

= a . ( b - c - d )

b, ab + ad - bc - bd 

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

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

Đúng thì tíck mk nha !!

a)ab−ac+dc−db=a(b+c)−d(b−c)=(b−c)(a−d)

b)ac+ad−bc−bd=a(c+d)−b(c+d)=(c+d)(a−b)

tick mình đủ 20 với 

ai ko giải được thì tick mk tick cho

A = ab - ac + ad

= a(b - c  + d)

B = ac + ad - bc - bd

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

= (a - b)(c + d) 

A=a.(b-c+d)

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

tick mình nha bạn

A=ab-ac+ad=a(b-c+d)

B=ac+ad-bc-bd=(ac+ad)-(bc+bd)=a(c+d)-b(c+d)=(c+d)(a-b)

ab-ac+ad = a(b-c+d)

ac+ad-bc-bd = a(c+d)-b(c+d) =(a-b)(c+d)

a) = a( b - c + d )

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

tick nha

a)a(b-c+d)

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

a) ab - ac + ad = a(b - c + d)

b) ac + ad - bc - bd

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

= (c + d) (a - b)

A,

ab-ac+ad=a(b-c+d)

B,

ac+ad-bc-bd=a(c+d)-b(c+d)=(a-b)(c+d)

ab-ac+ad

=a.(b-a+d)

b) ac+ad-bc-bd

  =c.(a-b)+d(a-b)

  =(a-b).(c+d)

xy+3x-7y=21

x(y+3)-7y+21=0

x(y+3)-7(y+3)=0

(y+3).(x-7)=0(còn lại tự làm ha)