The product of (3 - 4i) and is 25.

( 3 + 4i )

Step-by-step explanation:

For this problem, we need to know that i^2 = -1. With this, let's solve the multiplication problem.

So to get rid of the i, we know it needs to be squared. The question is, for the sun of the products do we have a -4i or a +4i? So we will test both.

( 3 - 4i )^2 ?= 25

( 3 - 4i )( 3 - 4i ) ?= 25

9 - 12i - 12i - 16 ?= 25

We can stop here since we know that 24i will never equal 25.

So let's try the -4i

( 3 + 4i )( 3 - 4i ) ?= 25

9 + 12i - 12i + 16 ?= 25

9 + 16 ?= 25

25 == 25

Thus, our term for this to be true is ( 3 + 4i ).

Cheers.

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls