Answer:
3) a=0
Explanation:
Distribute 7 through the parenthesis (2a-1) -> 14a-7-3= 10a-10-4a
Combine like terms -> 14a-7-3= 6a-10
Calculate the difference -> 14a-10=6a-10
Cancel out equal terms on both sides -> 14a=6a
Move 6a to the left -> 14a-6a=0
Combine like terms -> 8a=0
Divide both sides -> a=0
If you need help on the other ones lmk