简单数学题Thesumofthefirsttwotermsofa
The sum of the first two terms of a geometric gression is 35/2 and the third term is 14/3. Find the positive common ratio.
a1+a1q=35/2.............(1) a1q^2=14/3..............(2) 由(2)得,a1=14/(3q^2)代入(1) 14/(3q^2)+14/(3q)=35/2 28+28q=105q^2 15q^2-4q-4=0, q=2/3