@@iamtheboneofmysword728clarification: we were indeed given tools to solve this at 13/14 but i doubt most sgporeans wld be able to solve this if you picked one out at random. but yeah maybe at most theyll ask us to find x^2 + y^2 from this in an exam question.
@friepima499 That's true, you probably wouldn't see a question like this in sec 1 so the average student may not be able to solve it. While I don't recall my sec 1-2 exams I know that there are similar questions in the earlier sections of O level papers, which are the easier ones that test sec 1-2 concepts. If you pick out a sec 1 student getting As for math which isn't difficult, they'd probably be able to solve this though
you can solve for x by getting y from the first formula, and using it in the second. I.d., x + y = 12 -> y = 12 - x | xy = 10 -> x(12 - x) = 10 -> 12x - x² - 10 =0 -> x ≈ 11.1 or x ≈ 0.9