1. Which expressions are equal to a real number? Select all that apply
.
a. (-4i)?
b. (-3i) 12
C. (2 + 3i)?
d. (4 + 5i)(4 - 5i)
e. (6 + 8i)(8 + 6i)

real numbers: b, d

Step-by-step explanation:

a, 11 is a odd number --> (-4i)? isn't a real number

b, 12 is a even number --> (-3i)? is a real number

c, (2+3i)? = (-5+12i)? --> isn't a real number

d, (4+5i)(4-5i) = 41 --> is a real number

e, = 100i --> isn't a real number

hope this !

step-by-step explanation:

d = distance between moon and sun, which in this problem is the hypotenuse of a right triangle.  

the distance y is the side opposite to angle x in the right triangle.   use the definition of the sine function from basic trigonometry.

sin(x) = y/d ⇒

d = y/sin(x)

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk