Answer:
I think it is right but not sure
Let's plug in (18,10) into each answer choice until we find the one that has it as a solution.
A) 2x - y = 26
2(18) - 10 = 26
36 - 10 = 26
26 = 26
Your answer is A.
I'll just do the rest to show that you the they are incorrect.
B) x + y = 18
18 + 10 = 18
28 ≠ 18
C) 2x - 2y = 36
2(18) - 2(10) = 36
36 - 20 = 36
16 ≠ 36
D) x - y = -28
18 - 10 = -28
8 ≠ -28
Your answer is A) 2x - y = 26.
Answer:

Step-by-step explanation:
Use the square of a binomial theorem
= 
Now expand the given equation:

Hope this helps :)
Have a great day!
Answer:
E
Step-by-step explanation:
The problem says that triangle BDC lies in the plane k, which means that whatever angle is formed by another point beyond this plane with any of the three segments that form BDC (BD, DC, and BC) is the same as the angle formed by the line connecting the point and the plane.
Here, we're given that AD⊥DC, which means AD forms a 90° angle with DC. Then, since DC is already on the plane, we already know for sure that AD is definitely perpendicular to plane k.
Thus, the answer is E (none of these).
Answer:
201cm
Step-by-step explanation: