One number is 2 less than a number. twice the second number is 9 less than 3 times the first. find the two numbers

These are the starting equations:
x=y-2
2y=3x-9
Then you put one of the variables in terms of the other to find its value:
2y=3(y-2)-9
2y=3y-6-9
2y-3y=-6-9
-y=-15
y=15

x=y-2
x=15-2
x=13

check: x=y-2
13=15-2

true, so that's your answer, hope it helped!