Question

If x = 3 and y = -1, then 3x2 + 2xy - 5 = ? A: 18 B: 24 C: 12 D: 16

Answer 1

$x = 3 , \ y = -1 \\ \\ 3x^2 + 2xy - 5 = 3\cdot 3^2 + 2\cdot 3\cdot (-1)-5=\\ \\=3\cdot 9 -6-5=27-11=16 \\ \\ Answer : \ D: \ \ 16$

Answer 2

$3\cdot3^2+2\cdot3\cdot(-1)-5=27-6-5=16$