Question

4^x-1+4^x+4^x-1=21. ​

Answer 1

Step-by-step explanation:

4^x-1+4^x+4^x-1=21

4^x+4^x+4^x-1-1=21

3×4^x-2=21

Add 2 to LHS And RHS

So Now The Equation Would Be,

3×4^x-2+2=21+2

3×4^x= 23

Now divide both LHS and RHS by 3

3×4^x/3 = 23/3

now 3 cancels out an now the equation is

4^x = 23/3

Now by Applying exponent rules

xln(4) = ln(23/3)

xln(4)= ln(23/3): x = ln (23/3)/ 2ln (2)

x= ln (23/3)/2ln(2)