Question

5^x+25/5^x=10 sugestão faça 5^x=y

Answer 1

5^x+25/ 5^x =10
↓
5^x=y
↓
y+25/y=10
(y²+25)/y=10
y²+25=10y
y²-10y+25=0

Δ=b²-4ac
Δ=(-10)²-4*1*25
Δ=100-100
Δ=0(y'=y")

y=-b±√Δ/2a
y=-(-10)±√0/2*1
y=10/2
y'=y"=5


5^x=y
5^x=5
5^x=5^1
x=1

S={1}