(a + b + c)^2 + (a - b - c)^2 +( b - c - a) ^2 + (c - a - b)^2
= (a + b + c)^2 + (a + b - c)^2 + (a - b - c)^2 + (a - b + c)^2
= (a + b)^2 + 2c(a + b) + c^2 + (a + b)^2 - 2c(a + b) + c^2 +
(a - b)^2 - 2c(a - b) + c^2 + (a - b)^2 + 2c(a - b) +c^2
= 2(a + b)^2 + 2c^2 + 2(a - b)^2 + 2c^2
= 2[(a + b)^2 + (a - b)^2] + 4c^2
=2(2a^2 + 2b^2) + 4c^2
= 4(a^2 + b^2 + c^2)
Rut gon bieu thuc: (a-b+c)^2+2(a-b+c)(b-c)+(b-c)^2
rut gon bieu thuc
(a+b-c)2+(a-b+c)2-2(b-c)2
Rut gon bieu thuc : (a+b-c)2 + (a-b+c)2 -2(b-c)2
rut gon bieu thuc
(a+b)\(^2\)+(b+c)\(^2\)+(c+a)\(^2\)-3(a+b)(b+c)(c+a)
cho a,b,c khac nhau doi mot va 1/a+1/b+1/c=0.rut gon cac bieu thuc
N=bc/a^2+2bc+CA/B^2+2AC+AB/C^2+2AB
rut gon bieu thuc sau:
(a2+b2+c2)-(a2+b2+c2)2
rut gon bieu thuc S = a-b/a+b + b-c/b+c + c-a/c+a + (a+b)(b-c)(c-a) / (a+b)(b+c)(c+a)
giai dum minh bai nay voi :c=x/2x-2+x^2+1/2-2x^2
a)tim x de a co nghia
b)rut gon bieu thuc c
c)tim gia tri cua x de bieu thuc kia =1/2
giúp mình cảm ơn nhìu nha !
cho 2 bieu thuc A=x+x^2/2-x va B=2x/x+1+3/x-2-2x^2+1/x^2-x-2 a, tinh gia tri cua A khi /2x-3/=1 b,tim dieu kien xac dinh va rut gon bieu thuc B c,tim so nguyen x de P=A.B dat gia tri lon nhat
mk dang can gap
