So for this I would set up a ratio. 1/10=x/380 then you cross multiply so 1x380=10x. Then solve the equation so 380/10=x and you get 38in. Hope my explanation helped!
It'll be 639.500 or just 639.5
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
