9x+18+3x=1
9x+18= -2
9x= -20
x= - 20/9
find the error in the solution and then solve correctly

error is in second step.

Step-by-step explanation:

The given equation is 9x + 18 + 3x = 1

Now we will solve this equation and compare it with the given answer.

9x + 18 + 3x = 1

12x + 18 = 1

12x = (-17)

x =

Now we find the error is in second step.

  or  

step-by-step explanation:

if the four friends split the cost, p, of the pizza evenly, then each friend pays one-fourth of the cost of the pizza.

the expression is   or