Answer:
4
Step-by-step explanation:
15 = 7 - /2x/
Subtract 7 from both sides ( if it was negative you would add it)
(15-7) = (7 - 7) -/2x/ now the seven is no longer there
8 = -/2x/
Now divide 2 from both sides
( 8 / 2 ) = - /(2 / 2)x/
4 = -/x/
4 = -x
Now the two is no longer there but the x would still be there because you divided it by 2 and not 2x