The equation is 104 = y 67.

According to Addition property of equality: if a = b, then a + c = b + c.

104 + 67 = y 67 + 67             (Add 67 to each sides)

  y = 104 + 67                               (Additive inverse property: 67 + 67 = 0)

  y = 171                                       (Add: 104 + 67 = 171)

Check:

To check the solution, substitute  y = 171 in original equation.

 104 = y 67104 = 171 67

  104 =  104                                 (Subtract: 171 67 = 104)

Compare the values, the equation is true. The solution is  y = 171.

The value of y = 171.