Question

Which expression is equivalent to (4 + 7i)(3 + 4i)?

Answer 1

=12 + 16i + 21i + 28i^2

=12 + 37i + -28

=37i - 16

Answer 2

we have

$(4+7i)(3+4i)$

remember that

$i^{2} =-1$

Applying the distributive property

$(4+7i)(3+4i)=4*3+4*4i+7i*3+7i*4i \\=12+16i+21i+28 i^{2}\\= 12+37i+28*(-1) \\=12-28+37i\\=-16+37i$

therefore

the answer is

$-16+37i$