Answer:
x=9 and the missing angle is 44

If 2x+y=5, then y=5-2x, so he substituted 5-2x correctly.
x+4x=5x, so he combined like terms correctly.
If 5x-10=10, then 5x=10+10 -> 5x=20, so he subtracted 10 from the right side instead of adding 10 to the right side.
The answer is C.
Here's the correct solution:
Answer:
10
Step-by-step explanation:
Assuming that each square is one unit, you plug it into the distance formula.
Answer:
Not C, Not A, most likely B
Step-by-step explanation:
Its less than 90 because its and acute, meaning its smaller, so you can already knock off C.
We will need like a graph for that