To solve this equation you need to find the value of x. You can do this by using inverse operations. and getting x alone. x/4=5 the opposite of division is multiplication so we multiply 5 by 4 x=5*4 we now have x alone and must solve the rest of the equation 5*4=20 There for x=20 The recipe originally made 20 servings.
I hope this helped:) If you have any questions pleas comment and i will do my best to answer and/ or explain :)