A level Maths help

Can anyone help me with question 6?

If we denote the first term as $a$ and the common ratio as $r$, can you convert the following into mathematical equations?

- Sum of the first three terms is $\dfrac{95}{4}$

- Sum of the first four terms is $\dfrac{325}{8}$

P.S. I've converted mixed fraction form into improper fractions for you. Avoid mixed fractions whenever possible at A-Level.

Ok

Okay so I've just did that, then I took them away to get ar^3 = 677/40. What do i do now?

It is actually more useful to use the formula $S_n = \dfrac{a(1-r^n)}{1-r}$. Then divide one equation by the other rather than subtract.