cho a/c = c/b chung minh b^2 -a^2 /a^2 +c^2 = b-a/a
cho a/c=c/b chung minh rang
a, a^2+c^2/b^2+c^2=a/b
b, b^2-a^2/a^2+c^2=b-a/a
cho a^2(b+c)=b^2(a+c)=2015
a,chung minh a*b*c=-2015
b,tinh c^2(a+b)
cho a/b=c/d Chung minh a^2+b^2 / a^2 -b^2 = c^2+d^2 /c^2 -d^2
cho 4 so a,b,c,d sao cho a.c=b^2,b.d=c^2. chung minh a/d=a^2+b^2+c^2/b^2+c^2+d^2
CHo ti le thuc a/b=c/d Chung minh rang (a+b/c+d)^2=a^2+b^2/c^2+d^2
cho a/c = c/b chung minh b^2 -a^2 /a^2 +c^2 = b-a/a.
Cho a,b,c la cac so duong .Chung minh rang:
a^2016+b^2016+c^2016 >hoac=(b+c).a^2015/2+(c+a).b^2015/2+(a+b).c^2015/2
cho: a/b=c/d . chung minh rang a2+b2/b2+c2=a/c