Question

If a^2 + b^2=65 and ab=28 then what would be the value of a+b

Answer 1

$heya \\ \\ \\ a {}^{2} + b {}^{2} = (a + b) {}^{2} - 2ab \\ \\ \\ \\ (a + b) {}^{2} - 2ab = 65 \\ \\ \\ \\ (a + b) {}^{2} - 2 \times 28 = 65 \\ \\ \\ \\ (a + b) {}^{2} = 65 + 56 \\ \\ \\ \\ (a + b) {}^{2} = 121 \\ \\ \\ \\ (a + b) = 11 \: \: \: \: \: or \: \: \: \: \: (a + b) = - 11$