Cho a, b, c \(\in\)R và a, b, c\(\ne\)0 thoả mãn b^2=ac. CMR
\(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
Cho a,b,c thuộc R và a,b,c khác 0 thỏa mã : \(b^2=ac\)
CMR: \(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(a+2007c\right)^2}\)
Cho a,b,c, thuộc R và a,b,c khác 0 thỏa mãn \(^{b^2}\) =ac .CMR: \(\frac{a}{b}\) =\(\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
cho a, b, c \(\in\)R và a, b, c \(\ne0\) thỏa mãn \(b^2=ac\). CMR: \(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
Cho a,b,c \(\ne\)0 thỏa mãn b2=ac. Chứng minh rằng: \(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
Ta co:\(b^2=ac\Leftrightarrow\frac{a}{b}=\frac{b}{c}\)
\(=\frac{2007b}{2007c}=\frac{a+2007b}{b+2007c}\)
\(\Rightarrow\left(\frac{a+2007b}{b+2007c}\right)^2=\left(\frac{a}{b}\right)^2=\frac{a}{b}\times\frac{b}{c}=\frac{a}{c}\)
Vậy \(\frac{a}{c}=\left(\frac{a+2007b}{b+2007c}\right)^2\left(đpcm\right)\)
cho \(a;b;c\in R\) và a;b;c thỏa mãn b2=ac
CMR ............=\(\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
b2 = ac => \(\frac{a}{b}=\frac{b}{c}\)
Áp dụng tính chất của dãy tỉ số bằng nhau ta có: \(\frac{a}{b}=\frac{b}{c}=\frac{a+2007b}{b+2007c}\)
=> \(\left(\frac{a+2007b}{b+2007c}\right)^2=\frac{a+2007b}{b+2007c}.\frac{a+2007b}{b+2007c}=\frac{a}{b}.\frac{b}{c}=\frac{a}{c}\)
Vậy \(\frac{a}{c}=\left(\frac{a+2007b}{b+2007c}\right)^2\)
cho a,b,c thuộc R và a,b,c khác 0 thỏa mãn \(b^2=ac\).chứng minh rằng\(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
Cho a,b,c \(\varepsilon\)R và a,b,c #0thõa mãn b2=ac.C/minh rằng \(\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
Ta có: \(b^2=a.c\Rightarrow\frac{a}{b}=\frac{b}{c}\)
Đặt \(\frac{a}{b}=\frac{b}{c}=k\left(k\in R\right)\)
\(\Rightarrow a=b.k\); \(b=c.k\)
\(\frac{a}{c}=\frac{a.c}{c.c}=\frac{b^2}{c^2}\left(1\right)\)
\(\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}=\frac{\left(b.k+2007b\right)^2}{\left(c.k+2007c\right)^2}=\frac{\left[b\left(k+2007\right)\right]^2}{\left[c.\left(k+2007\right)\right]^2}=\frac{b^2.\left(k+2007\right)^2}{c^2.\left(k+2007\right)^2}=\frac{b^2}{c^2}\left(2\right)\)
Từ \(\left(1\right)\) và \(\left(2\right)\) \(\Rightarrow\frac{a}{c}=\frac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\) \(\left(đpcm\right)\)
Cho 3 số dương a,b , c thoả mãn \(b\ne c,\sqrt{a}+\sqrt{b}\ne\sqrt{c}v̀aa+b=\left(\sqrt{a}+\sqrt{b}-\sqrt{c}\right)^2\)
Chứng minh rằng; \(\frac{a+\left(\sqrt{a}-\sqrt{c}\right)^2}{b+\left(\sqrt{b}-\sqrt{c}\right)^2}=\frac{\sqrt{a}-\sqrt{c}}{\sqrt{b}-\sqrt{c}}\)
Cho \(a,b,c\in R\) và \(a,b,c\ne0\) thỏa mãn \(b^2=ac\) . Chứng minh rằng :
\(\dfrac{a}{c}=\dfrac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)
\(b^2=ac\Rightarrow\dfrac{b}{a}=\dfrac{c}{b}\)
Đặt :\(\dfrac{b}{a}=\dfrac{c}{b}=k\Rightarrow b=ak\)
\(c=bk\)
\(\Rightarrow c=akk=ak^2\)
VT\(=\dfrac{a}{c}=\dfrac{a}{ak^2}=\dfrac{1}{k^2}\)
VP \(=\dfrac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}=\dfrac{\left(a+2007ak\right)^2}{\left(b+2007bk\right)^2}\)
\(=\dfrac{\left[a\left(1+2007k\right)\right]^2}{\left[b\left(1+2007k\right)\right]^2}=\dfrac{a^2\left(1+2007k\right)^2}{b^2\left(1+2007\right)^2}=\dfrac{a^2}{b^2}=\dfrac{a^2}{\left(ak^2\right)}=\dfrac{a^2}{a^2k^2}=\dfrac{1}{k^2}\)
\(\Rightarrow VT=VP\Rightarrow\dfrac{a}{b}=\dfrac{\left(a+2007b\right)^2}{\left(b+2007c\right)^2}\)