chung minh dang thuc
[a+b].[c+d]-[a+d].[b+c]=[a-c].[d-b]
chung minh dang thuc sau la sai:
a+b+c-d=a-b+c-d
chung minh dang thuc
a, [ b+c ]-b. [ a -c]= [ a+ b].c
b, [b-c ]-a. [b+d]=a.[c+d]
chung minh dang thuc
a.( b - c ) - a ( b + d ) = -a ( c + d )
giup minh voi lam onnnnn.......
chung minh dang thuc:
a, - ( 49 - 3x ) + 41 = 3x - 8
b, - ( a + b + c + 1 ) + ( b - c ) - ( a - c - 1 ) = - c - 2a
Cho a+b=c+d va a^2+b^2=c^2+d^2.Chung minh rang:a^2022+b^2022=c^2022+d^2022
Moi nguoi giup minh voi,minh dang can gapBo dau ngoac roi rut gon bieu thuc :
a) - ( -a + c - d ) - ( c- a + d )
b) - ( a + b - c + d ) + ( a - b - c - d )
c) a( b- c -d ) - a( b + c - d )
Giup minh nhe minh dang can gap
chung minh cac dag thuc sau:
a, (-a) (b-c+d)= -ab+ac-ad
b, (a+b) (x+y)-(a+b).y=(a+b).x
c,(2-b+c)-a(2+c)=-ab
cho a chia het cho5,bchia het cho 5;chung minh rang (a4-b4) chia het cho5 dung cong thuc "hang dang thuc dang nho" cong thuc3