13x=80
13x/13 = 80/13
x=6 2/13

a. Liam should have added 3 to both sides of the equation rather than subtracting.
b. Liam did everything correctly.
c. Liam forgot to distribute the 6 to the 3.
d. Liam should have subtracted 13 from both sides of the equation rather than dividing.