Question

SIMPLIFY THE Expression
$3(m {} ^{2} + mn) + 6 - mn$
Find out its value when

$m = 3 \: and \: n = 6$
​

Answer 1

Step-by-step explanation:

$= 3(9 + 18) + 6 - 18 \\ = 3 \times 9 + 3 \times 18 + 6 - 18 \\ = 27 + 54 + 6 - 18 \\ = 87 - 18 \\ = 69$