Đáp án: Cho a/b=c/d chứng minh; a) c/a-c=b/b-d b) a/c= a+b/c+d c) 2a + 3a/ 2b+ 3d = 2a - 3c / 2b - 3d - a abab = cdcd <-> caca = dbdb <-> ca−cca−c = db−ddb−d b abab = cdcd <-> acac = bdbd= a+bc+da+bc+d c abab = cdcd=2a2b2a2b = 3c3d3c3d=−3c−3d−3c−3d=2a+3c2b+3d2a+3c2b+3d= 2a−3c2b−3d2a−3c2b−3d

a abab = cdcd <-> caca = dbdb <-> ca−cca−c = db−ddb−d b abab = cdcd <-> acac = bdbd= a+bc+da+bc+d c abab = cdcd=2a2b2a2b = 3c3d3c3d=−3c−3d−3c−3d=2a+3c2b+3d2a+3c2b+3d= 2a−3c2b−3d2a−3c2b−3d

a (a/b) = (c/d) (c/a) = (d/b) (c/a-c) = (d/b-d) b (a/b) = (c/d) (a/c) = (b/d)= (a+b/c+d) c (a/b) = (c/d)=(2a/2b) = (3c/3d)=(-3c/-3d)=(2a+3c/2b+3d)= (2a-3c/2b-3d)

Thiivo357

2 năm trước

Cho a/b=c/d chứng minh; a) c/a-c=b/b-d b) a/c= a+b/c+d c) 2.a + 3.a/ 2.b+ 3.d = 2.a - 3.c / 2.b - 3.d

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phuongnhiennguyen246

2 năm trước

a. $\frac{a}{b}$ = $\frac{c}{d}$

<-> $\frac{c}{a}$ = $\frac{d}{b}$

<-> $\frac{c}{a - c}$ = $\frac{d}{b - d}$

b. $\frac{a}{b}$ = $\frac{c}{d}$

<-> $\frac{a}{c}$ = $\frac{b}{d}$ = $\frac{a + b}{c + d}$

c. $\frac{a}{b}$ = $\frac{c}{d}$ = $\frac{2 a}{2 b}$ = $\frac{3 c}{3 d}$ = $\frac{- 3 c}{- 3 d}$ = $\frac{2 a + 3 c}{2 b + 3 d}$ = $\frac{2 a - 3 c}{2 b - 3 d}$