a/b+c=c/a+b=b/c+a
theo t/c dãy tỉ số bằng nhau,ta có
a/b+c=c/a+b=b/c+a=a+b+c/b+c+a+b+c+a=a+b+c/2.(a+b+c)=1/2
Vậy A=1/2
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tim A biet rang
A=\(\frac{a}{b+c}=\frac{c}{a+b}=\frac{b}{c+a}\)
tim A biet
\(\frac{a}{b+c}=\frac{c}{b+c}=\frac{b}{a+c}\)
Tim A biet : A=\(\frac{a}{b+c}=\frac{c}{a+b}=\frac{b}{c+a}\)
tim a,b,c biet\(\frac{1}{2}a=\frac{2}{3}b=\frac{3}{4}c\) va a-b=15
Tim x biet:
\(\frac{x-ab}{a+b}=\frac{x-bc}{b+c}=\frac{x-ca}{c+a}=a+b+c\\ \) (a khac -b ; b khac -c ; c khac -a)
biet x=\(\frac{a}{b+c}\)=\(\frac{b}{c+a}\)=\(\frac{c}{a+b}\)
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a] a+b+c=0
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a) tim a,b,c biet: \(\frac{a}{-2}\)=\(\frac{b}{3}\);\(\frac{b}{5}\)=\(\frac{c}{4}\)va a+2b+c=32
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Tim x biet Bai 1: Tim cap so (x,y) biet: frac{1+3y}{12}frac{1+5y}{5x}frac{1+7y}{4x}Bai 2; Cho frac{a}{b}frac{b}{c}frac{c}{a}va a,b,c khac ; a2012. tinh b,cBai 3: tim cac so x,y,z biet :frac{y+x+1}{x}frac{x+z+2}{y}frac{x+y-3}{z}frac{1}{x+y+z}Bai 4: Tim x, biet rang:frac{1+2y}{18}frac{1+4y}{24}frac{1+6y}{6x} giup minh di minh dang rat gap cam on
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Tim x biet
Bai 1: Tim cap so (x,y) biet: \(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
Bai 2; Cho \(\frac{a}{b}\)=\(\frac{b}{c}\)=\(\frac{c}{a}\)va a,b,c khac ; a=2012. tinh b,c
Bai 3: tim cac so x,y,z biet :
\(\frac{y+x+1}{x}\)=\(\frac{x+z+2}{y}\)=\(\frac{x+y-3}{z}\)=\(\frac{1}{x+y+z}\)
Bai 4: Tim x, biet rang:\(\frac{1+2y}{18}=\frac{1+4y}{24}=\frac{1+6y}{6x}\)
giup minh di minh dang rat gap cam on
Tim a,b,c biet \(\frac{a}{2}\)= b = \(\frac{c}{3}\)va a - 2b + c =210