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+d]-[a+d].[b+c]=[a-c].[d-b]
(a+b)(c+d)-(a+d)(b+c)=ac+bc+ad+bd-ab-ac-cd-bd
=bc+ad-ab-cd=a(d-b)-c(d-b)=(a-c)(d-b)
chung minh a+b/c+d=b+c/d+a (biet a+b+c+dang khac 0)
voi a,b,c,d la cac so duong thoa man a*b = c*d = 1. Chung minh bat dang thuc ( a+b )*( c+d ) + 4 >= 2( a+b+c+d )
voi a,b,c,d, la cac so duong thoa man a*b = c*d =1 chung minh bat dang thuc : ( a+b )*( c+d ) +4 >= 2*( a+b+c+d ) cac ban oi giup minh voi OK
chung minh dang thuc (a+b).(c+d)-(a+d).(b+c)
chung minh dang thuc sau la sai:
a+b+c-d=a-b+c-d
Không ai trả lời được à,câu này dễ mà
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 gapcho a/b=c/d chung minh (a- b)^2 /(c - d)^2 = ab/ cb
chung minh dang thuc
a.( b - c ) - a ( b + d ) = -a ( c + d )
giup minh voi lam onnnnn.......
a.(b-c)-a.(b+d)=-a.(c+d)
a.b-a.c-a.b+a.d=-a.(c+d)
(a.b-a.b)-(a.c+a.d)=-a.(c+d)
0-a.(c+d)=-a.(c+d)
-a.(c+d)=-a.(c+d)
Vậy a.(b-c)-a.(b+d)=-a.(c+d).