co ai biet ko? Neu biet thi giup mk voi
co ai biet ko? Neu biet thi giup mk voi
1. cho \(\frac{a}{b}=\frac{c}{d};\)(b,c,d khac 0)
cmr: \(\frac{a-b}{a+b}=\frac{c-d}{c+d}\); \(\frac{a\cdot b}{c\cdot d}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
cho a, b, c, d khac 0 va thoa man
ac=b^2; bd=c^2
chung minh \(\frac{a^3+b^3+c^3}{b^3+c^3+d^3}=\frac{a}{d}\)
cho a,b,c,d la 4 so khac 0 thoa man b^2 =ac va c^2=bd.Cmr\(\frac{a^3+b^3+c^3}{b^3+c^3+d^3}\)=\(\frac{a}{b}\)
cho ti le thuc\(\frac{a}{b}=\frac{c}{d}\) cmR
\(\frac{ab}{cd}=\frac{a^2-b^2}{c^2-d^2}\)va \(\left(\frac{a+b}{c+d}\right)^2\)=\(\frac{a^2-b^2}{c^2-d^2}\)
Cho a , b , c khac 0 va \(\frac{a+b}{ab}=\frac{b+c}{bc}=\frac{c+a}{ca}\) Tinh C=\(\frac{ab^2+bc^2+ca^2}{a^3+b^3+c^3}\)
CMR nếu \(\frac{a^2+b^2}{c^2+d^2}=\frac{ab}{cd}\)(a,b,c,d khác 0). CMR \(\frac{a}{b}=\frac{c}{d}\)hoặc \(\frac{a}{b}=\frac{d}{c}\)
cho \(\frac{a^2+b^2}{c^2+d^2}=\frac{ab}{cd}\)với a,c,b,d khác 0,c khác +-d. CMR \(\frac{a}{b}=\frac{c}{d}hoặc,\frac{a}{b}=\frac{d}{c}\)
1.Biết : \(\frac{a^2+b^2}{c^2+d^2}=\frac{ab}{cd}\)với a ,b ,c ,d khác 0
CMR: \(\frac{a}{b}=\frac{c}{d}ho\text{ặc}\frac{a}{b}=\frac{b}{c}\)
Cho : \(\frac{a}{b}=\frac{c}{d}CMR:\)\(\frac{ab}{cd}=\frac{a^2-b^2}{c^2-d^2}v\text{à}\left(\frac{a+b}{c+d}\right)^2=\frac{a^2+b^2}{c^2+d^2}\)