- 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