Question

equação exponencial

Answer 1

2^x+3+ 2^x-1= 20
corta-se as bases
x+3+ x-1= 20
2x= 20-3+1
2x= 18
x= 18/2
x= 9

Answer 2

$2^{x+3}+2^{x-1}=20 \\ \\ 2^3.2^x+ \frac{2^x}{2}=20 \\ \\ 8.2^x+ \frac{2^x}{2}=20 \\ \\ 16.2^x+2^x=40 \\ \\ 17.2^x=40 \\ \\ 2^x= \frac{40}{17}$