Question

Sa se rezolve in R ecuatia:
2*5^(x+1)-5^x=45

Answer 1

5^(x+1)=5*5^x
Ecuatia  devine
10*5^x-5^x=45
9*5^x=45
5^x=5
x=1

Answer 2

$\displaystyle 2 \cdot 5^{x+1}-5^x=45 \\ 2 \cdot 5^1 \cdot 5^x-5^x=45 \\ 5^x(10-1)=45 \\ 5^x \cdot 9=45 \\ 5^x= \frac{45}{9} \\ 5^x=5 \\ x=1$