7/y....the coefficient of y is 1
any time u have a variable by itself, whether it is x or y or any letter, the coefficient is gonna be 1
1) 16n - 5
2) 4a + 3b
3) -3c + 27 + 4d
4) 2x - 7y + 3
5) 21x + 14x(second power)
the math behind it:
your equation looks like this: .25x = 10
then you divide both sides by .25 and then ur equation looks like this: x=40
by the way the variable x stands for the number you are looking for. and since x=40, the number you are looking for is 40
well i hope i helped!