Question

One number is 18 more than three times another number. The difference in the numbers is 54. Find the numbers

Answer 1

The equations would be:
x=18+3y
x+y=54
(substitute x in the second equation with 18+3y)
18+3y+y=54
(combine like terms and solve for y)
y=9
(plug y into the second equation to find x)
x+9=54
x=45