Answer: 
Step-by-step explanation:
You have the equation 
.
Then, to solve for the variable 
from the equation you need:
Make the subtraction of the right side of the equation:
(As the denominators are 1 and 
, the least common denominator is )
Multiply to both sides:
Add 
to both sides:
And finally divide both sides by 
:
90+55+75+60+80+90=450
450/6=75
In order to create a line parallel to line “I”, rotate line “I” 180° about points “F”. This can be done clockwise or counterclockwise.
First, you combine like terms: x+3x=4x: 12+4x=18-2x
Second, you add the 2x to each side (inverse operation): 12+6x=18
Third, you subtract 12 from 18 to cancel out the 12 (inverse operation): 6x=6
Fourth, you divide each side by 6 to find the value of x
The answer is x=1
Check the picture below
if your calculator is in Degree mode, you'll get the angle in degrees, if in Radian mode, you'll get radians get taking the inverse sine, so you know
