Question

Cho a/2= b/5 = c/7

Tính P = a-b+c/a+2b-c

mk đang gấp á giúp xí nhan TvT

Answer 1

Đặt a/2=b/5=c/7=k

=>a=2k; b=5k; c=7k

\(P=\dfrac{a-b+c}{a+2b-c}=\dfrac{2k-5k+7k}{2k+10k-7k}=\dfrac{4}{5}\)

Answer 2

\(\dfrac{a}{2}=\dfrac{b}{5}=\dfrac{c}{7}=\dfrac{a-b+c}{2-5+7}=\dfrac{a+2b-c}{2+10-7}\\ \Rightarrow A=\dfrac{2-5+7}{2+10-7}=\dfrac{4}{5}\)