Question

Is this the correct way to expand and are the answer correct??

Answer 1

No 
for example (question 1),
3(2a - 5) you multiply the numbers inside the parenthesis ().
so it will be 6a - 15
And if there is a negative number in front of the parenthesis, you multiply that too
-1(2x-5) will be -2x+5
negative times negative will be positive!