Solve ax-5=b for a. so which one is right a, b,c or d

It would be c

ax-5=b What you have to do is get a to be by itself

So you would add 5 to both sides:
ax-5(+5)=b(+5) = ax=b+5

And then divide x by both sides. You divide because a is multiplied by x on the left side, so to move it to the other side you’d have to do the opposite and divide:
ax /x=b+5 /x

Answer is C ... a=(b+5) /x