Question

Brainiest to whoever gets this right first! 20 points!

Answer 1

You know the roots to the quadratic, so you know how the quadratic can be factorized:

$z^2+az+b=(z-(-7+2i))(z-(-7-2i))=(z+7-2i)(z+7+2i)$

Expanding the right side gives

$z^2+az+b=z^2+14z+4$

Matching up the coefficients tells us $a=14$ and $b=4$, so $a+b=18$.