Áp dụng t/c dãy tỉ số bằng nhau , ta có :
a/b = b/c = c/d = (a + b + c)/(b + c + d).
Suy ra : (a/b)^3 = (a+b+c/b+c+d)^3
Vậy (a+b+c/B+c+d)^3 = (a/b)^3 = (a/b).(a/b).a/b) = (a/b).(b/c).(c/d) = a/d (do rút gọn)
Cho a/b = b/c = c/d . CHung minh (a+b+c / b+c+d ) ^3 = a/d
cho a/b=b/c=c/d chung minh rằng a^3+c^3-b^3/c^3+b^3-d^3=a/d
Cho a/b = b/c = c/d (b,c,d # 0). Chung minh rang
a^3 + b^3 + c^3/ b^3+ c^3 + d^3 =a/b
cho a/b=c/d chung minh a-b/a+b=c-d/c+d
cho a/b=c/d chung minh a-b/a+b=c-d/c+d
cho a/b = c/d chung minh
1 a . ( b - d ) = ( a - c ) . b
2 ( a + c ) . d = c . ( b + d )
biet (a+b+c+d).(a-b-c+d)=(a-b+c-d).(a+b-c-d) chung minh a/c=b/d
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)
cho a/b=c/d Chung minh a^2+b^2 / a^2 -b^2 = c^2+d^2 /c^2 -d^2
