Question

12. If a+b=11 and ab=30, then find the value of (a2+b2)
O 61
O 21
24
O 81

Answer 1

$hey \: mate \: thank \: for \: the \: question \\ hope \: it \: helps \\ (a + b) {}^{2} = a {}^{2} + b {}^{2} + 2ab \\ given \\ (a + b) = 11 \: \: \: \: \: ab = 30 \\ (a + b) {}^{2} = a {}^{2} + b {}^{2} + 2ab \\ (11) {}^{2} = a {}^{2} + b {}^{2} + 2 \times 30 \\ 121 = a {}^{2} + b {}^{2} + 60 \\ 121 - 60 = a {}^{2} + b {}^{2} \\ 61 = a {}^{2} + b {}^{2}$