Answer:
b.
42+x+90+8=180° linear pair
x=180-140=40°
<em>x=40°</em>
c.
10+x+90+3x=180 linear pair
4x=180-100
x=80/4=20
<em><u>x=20</u></em>°
2.161616 = 2.161616/1 =21. 61616/10 = 216.1616/100 = 2161.616/1,000
= 21616.16/10,000 = 216161.6/100,000 = 2161616/1,000,000
As a mixed number = 2(161616/100,000)
So 2x+12=5x-9
you want all of the unknowns on one side and all of the known values on the other or
subtract 2x from both sides
12=3x-9
add 9 to both sides
21=3x
divide both sides by 3
7=x