Question

if 3^x-3^x-1=18, find x​

Answer 1

Answer:

For this question we need to find the value of x, it could be found by using basic algebraic rules.

3^x-3^(x-1)=18

i.e. 3^x-3^x * 3^-1=18

i.e. 3^x-(3^x/3)=18

Multiplying throughout by 3, we get,

3*3^x-(3^x)=18*3

let us substitute 3^x=m, we have,

3m-m= 54

i.e. 2m=54

i.e. m=27

Now, resubstituting, m=3^x, we have,

3^x=27

i.e. 3^x=3^3

i.e. x=3.