I wonder what language this is, with the question numbers to the right of the question with dots on the left. It's also odd the constants are written to the right of the parentheses. But we persevere.
Anyway we can do three for you; you're on your own for the rest.
41.
That would usually be written
We can distribute first or divide first; here it's easier to divide both sides by 2:
Answer: 5
That checks. The answer key gives it as .5, I guess that's a period after the 5 in this language not a decimal point.
42.
Answer: -2
43.
Answer: -4