Qu: If a pounds of sugar and b pounds of coffee together cost c cents, while d pounds of sugar and e ppunds of coffee together cost f cents. what is the price of one pound of each?

I am trying to use simultaneous equations to do it but i cannot find a way to do it.

$ a + b = c$

$ d + e = f$

the problem is that if i do this:

$ae + be = ce$

$db + be = fb$

I can only eliminate be but i am stuck with this:

$ae - db = ce - bf$

is there something i am not seeing.