Answer: 
Step-by-step explanation:
Given
The expression is

Use identity 
Apply identity

Answer:
x=10 degrees
Step-by-step explanation:
2x+8+62=90
2x+70=90
2x=20
x=10
Answer:
Step-by-step explanation:
180
Answer:
x=0
Step-by-step explanation:
4 ( 2.5) ^x = 4
Divide each side by 4
4/4 ( 2.5) ^x = 4/4
( 2.5) ^x = 1
Take the log of each side
log ( 2.5) ^x = log (1)
x log ( 2.5) = log 1
x log (2.5) = 0
Divide each side by log (2.5)
x = 0
5y = 135....divide both sides by 5
y = 135 / 5
y = 27 <==