You should not be struggling with this one. You had better step up your studies. Do NOT forget your basic algebra!

If x = Actuarial Present Value of an n-year term insurance paying $1 at the end of the year of death, and

If y = Actuarial Present Value of an n-year pure endowment of $1, then we have:

750x + 750y = 625

300x + 500y = 300

You need 1000x + 1000y = ??

You can write all the fancy symbols you want, but this is a basic algebra problem.