a+b/a-b=c+d/c-d chung minh a^2=b*c giup mik vs
cho ham so f(x)=-4*x^3+x. chung minh f(-a)=-f(a)
GIUP MK VS BAI NAY MK CUG CAN RAT GAP A GIUP MK DI MN OI!!!!
cho day ti so (2*a+b+c+d)/a=(a+2*b+c+d)/b=(a+b+2*c+d)/c=(a+b+c+2*d)/d tinh A=(a+b)/(c+d)+(b+c)/(d+a)+(c+d)/(b+a)+(d+a)/(b+c)
Bai 1: cho a/b = c/d chung minh rang:
a2- b2/ c2- b2 = ab/cd
Giup mk vs ti nua mk nop r!
Đặt a/b=c/d=k
=>a=bk; c=dk
\(\dfrac{a^2-b^2}{c^2-d^2}=\dfrac{b^2k^2-b^2}{d^2k^2-d^2}=\dfrac{b^2}{d^2}\)
\(\dfrac{ab}{cd}=\dfrac{bk\cdot b}{dk\cdot d}=\dfrac{b^2}{d^2}\)
Do đó: \(\dfrac{a^2-b^2}{c^2-d^2}=\dfrac{ab}{cd}\)
chung minh: a^2 + b^2 - 3ab /c^2 + d^2 - 3cd = (2a-b)^2 / (2c-d)^2
giup mk vs nhe mina thanhs nhieu
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 gapvoi 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 to neu a/b < c/d (b>d>0) thi -a/b < c/d < a-c/b-d
giup minh nhe
giờ này bạn mí đăng thì mai mí có câu trả lời
Cho a=b+c va c=bd/b-d. Chung minh rang : a/b=c/d
giup minh nhanh len nhe
cho 2 p/s a/b vs c/d (a,b,c,d la cac so nguyen duong ) chung minh rang neu a/b < c/d thi b/a > d/c
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).