Question

if a^2+b^2=20 and ab=5 then find the value of a_b

Answer 1

${a}^{2} + {b}^{2} = 20 \\ ab = 5 \\ {(a - b)}^{2} = {a}^{2} + {b}^{2} + 2ab \\ = 20 + 10 = 30 \\ a - b = \sqrt{30}$