Expand:
Which becomes (from the rules of indices - look at the first term):
Now use the hint and substitute
So:
Can you solve for and put the solution back in terms of now?
9^x+1 - 13(3^x) + 4 =0
Use y = 3^x
OK so i start and reached to this point
3^2(x+1) - 13(3^x) + 4 = 0
3^2x+2 - 13(3^x) + 4 = 0
I need some help to proceed, thanks in advance