C.
You distribute both the 2 and the -, combine like terms, add three to both sides and then divide out the 3 from 3 on both sides
Pythagorean therom!
east and the north make a right angle
a^2 + b^2 = c^2
(11)^2 + (2)^2 = c^2
121 + 4 = c^2
125 = c^2
11.2 miles = c
In 2005 there were 9million bicycles in Beijing
Sum of linear pair of angles = 180°
so
<EFG + <GFH = 180°
2n + 21 + 4n + 15 = 180°
6n + 36 = 180°
6n = 144
n = 24
<EFG = 2(24) + 21 = 69°
<GFH = 4n + 15 = 4(24) + 15 = 111°
45degrees because angles can not be negative