Question

3^(x+2)-2*3^(x+1)+3^x<12

Answer 1

3^(x+2) - 2*3^(x+1) + 3^x < 12
3^x * 9 - 2*3^x * 3 + 3^x < 12
3^x ( 9 - 6 + 1) < 12
3^x *4 < 12
3^x < 3^1
x < 1