The answer is D. 64. Have a nice day!
Complementary angles are those angles whose sum is 90 degree.
The measurement of two complementary angles are

There sum have to be 90 degree. That is

Combining like terms ,

Moving 20 to right side

Dividing both sides by 5

So the measurement of the angles are

Answer:
1. 50%
2.100%
3.0%
4.100%
Step-by-step explanation:
Use https://www.mathsisfun.com/data/standard-deviation-calculator.html for later references.
All to one side:
4x^2-32x+64 = 0,
divide by 4:
x^2 -8x + 16 = 0
apply formula or see that it is (x-4)^2!, so only x =4 is a root and it is double.
Answer:
4
the fourth expression is a rational