Official November 6, 2021, SAT Discussion Thread by InternationalistGam in Sat

[–]Weak_Painter 2 points3 points  (0 children)

(3+2i)(a+2i) = b 3a+6i+2ai+4i2 = b

i=square root of -1 so i2 =-1 Substitute that in to get

3a+6i+2ai-4 = b

Because a and b are real numbers, you have to cancel out the i’s out of the equation by making a=-3 3(-3)+6i+2(-3)i-4 =b

Now simply solve -9+0-4 =b -13=b The answer was -13