[질문] x제곱+y제곱=25 xy=12 2x+y=10 x,y어떻게풀어요?

x2+y2=(x+y)제곱-2xy(곱셈공식변형) -> 25=(x+y)제곱-24 -> (x+y)제곱=49 -> x+y=7 / 2x+y=10 <-> x+y=7 (연립하면) x=3 / y=4 와아.. 꽤 복잡하네요^^;;