# of the task
The variable I represents negative number, so is 7i, since is +7 or -7. The answer is D.
Here we need to perform regular multiplication (3+4i)*(5+8i)= 15+24i+20i+32i^2, and then add similar components and re-write, 32i^2+44i+15. This answer matches with B.
In order to factor we need to think of two numbers that would fit into equation (x+Z)(x+Y), Z and Y are the two numbers. Z*Y should be -27 and Z+Y should be -6. Such numbers can be -9 and +