Question

a three digit number has ten digit two greater than the units digit and the hundreds digit one greater than the tens digit. the sum of the tens and the hundreds is three times the units digit. what is the number

Answer 1

xyz is the number.
y=2+z
x=y+1
x+y=3z

putting them in matrix form
0,1,-1,2
1,-1,0,1
1,1,-3,0
subtract 2 from 3
0,2,-3,-1
multiply 1 by 2 and subtract from above
0,2,-2,4
0,0,-1,-5
or z=5
then from 1), y=7 and you can solve for x.