Two meters is greater because there are about 79 inches in two meters and when you do 6 x 12 you get 72 inches, so six feet are less than two meters. Vice versa if you wanted the smaller length.
All triangles add up to 180 degrees. Since sines can't be a negative, you need to add -130 to 180. The answer to this question would be sine 50 degrees.
The denominator in each term of the series is a square number, but neither

nor

are squares. So none of (1), (2), and (4) can be correct. The answer must be (3).
Answer:
1. Isolate
2. Closed
3. Reversed
If you have more problems with things similar to this, I recommend this website, it gives a detailed description on how to solve the equations:
https://www.mathsisfun.com/algebra/inequality-solving.html
There is a 7 in both 7x and 7 so you will take that out.
7 (x+1)
Then there is an x in both x2 and 2x so you take that out.
x (x+2)