Question

If x minus y = 25 and xy = to 24 find the value of x + y

Answer 1

$(x - y) = 25 \\ xy = 24 \\ (x + y) {}^{2} = (x - y) {}^{2} + 4xy \\ = (25) {}^{2} + 4 \times 24 \\ = 625 + 96 \\ = 721 \\ hence \: (x + y) = 721$