Toán Lớp 7: a+b/a-b=c+a/c-a a^2+c^2/b^2+a^2=c/b cm nha đk a^2=bc

Question

Toán Lớp 7:  a+b/a-b=c+a/c-a a^2+c^2/b^2+a^2=c/b  cm nha đk a^2=bc

cattien · Answer

1)$ frac{a+b}{a-b}$=$ frac{a(a+b)}{a(a-b)}$=$ frac{a&sup2;+ab}{a&sup2;-ab}$=$ frac{bc+ab}{bc-ab}$=$ frac{b(c+a)}{b(c-a)}$=$ frac{c+a}{c-a}$   &rArr;$ frac{a+b}{a-b}$=$ frac{c+a}{c-a}$   2)$ frac{a&sup2;+c&sup2;}{b&sup2;+a&sup2;}$=$ frac{bc+c&sup2;}{bc+b&sup2;}$=$ frac{c(b+c)}{b(c+b)}$=$ frac{c}{b}$   &rArr;$ frac{a&sup2;+c&sup2;}{b&sup2;+a&sup2;}$=$ frac{c}{b}$   Xin c&acirc;u trả lời hay nhất ạ     #Murad

truongthanhhung · Answer

$ frac{a+b}{a-b}$=$ frac{a(a+b)}{a(a-b)}$=$ frac{a&sup2;+ab}{a&sup2;-ab}$=$ frac{bc+ab}{bc-ab}$=$ frac{b(c+a)}{b(c-a)}$=$ frac{c+a}{c-a}$   Vậy $ frac{a+b}{a-b}$=$ frac{c+a}{c-a}$   Đc 1 c&acirc;u nh&aacute;   C&acirc;u 2:   $ frac{a&sup2;+c&sup2;}{b&sup2;+a&sup2;}$=$ frac{bc+c&sup2;}{bc+b&sup2;}$=$ frac{c(b+c)}{b(c+b)}$=$ frac{c}{b}$   Vậy $ frac{a&sup2;+c&sup2;}{b&sup2;+a&sup2;}$=$ frac{c}{b}$   Xong 2 c&acirc;u nh&aacute;