Step-by-step explanation:
the answer is:
x=180-90-70=20°
Get on algebra calculator (mathpapa) and you should get the answer
Answer:
Step-by-step explanation:
2.A
Answer: (D) 
Explanation:

Just a note on writing down these expressions: I recommend using parentheses whenever you can to avoid misinterpretation. An expression 1/x-1/y / 1/x+1/y could be interpreted by someone as 1/x-(1/y / 1/x)+1/y, which is a different thing.