how will u subtract 678 - 8y = - 23

Answer 1

Perhaps what you really want to ask is "How do you solve for y?"

678 - 8y = -23

Get y by itself on one side. Subtract 678 from both sides and get

-8y = -23 - 678

Divide both side by -8 and get

y = (-23 - 678) / (-8) = ?

You finish from here.