Question

UFBA - Sendo a = -4 + 3i , b = 5 - 6i e c = 4 - 3i , o valor de a . c + b é???

Answer 1

$[tex](-4+3i).(4-3i)+5-6i \\ -16+12i+12i-9i^{2} +5-6i \\ -9i^{2}+24i-6i-11+5 \\ o- valor de a.c+b = -9i^{2}+18i-6$[/tex]

Answer 2

$ac+b=(-4+3i)(4-3i)+(5-6i)\\ac+b=-(4-3i)(4-3i)+5-6i\\ac+b=-(4-3i)^{2}+5-6i\\ac+b=-(4^{2}-2\cdot4\cdot3i+[3i]^{2})+5-6i\\ac+b=-(16-24i+9i^{2})+5-6i\\ac+b=-(16-24i-9)+5-6i\\ac+b=-(7-24i)+5-6i\\ac+b=-7+24i+5-6i\\\\\boxed{\boxed{ac+b=-2+18i}}$