Question

What is the value of the expression 2ab + 3bc + 4ac, when a = b =1, c = -1 ?​

Answer 1

$= 2ab + 3bc + 4ac$

$when \: a =1 , \: b =1 \: , \: c = -1$

$= 2(1)(1) + 3(1)( - 1) + 4(1)( - 1)$

$= 2 - 3 - 4$

$= 2 - 7$

$= - 5$