Question

(CESGRANRIO) O número de raízes reais de 3 = 1 é:

a) 0

b) 1

c) 2

d) 3

​

Answer 1

Resposta:

Duas raízes reais..

Explicação passo-a-passo:

$3^(2x^2-7x+5)=1 \\\\3^(^2^{x^{2}-7X+5}^) = 3^0 \\2x^{2} -7x+5 = 0\\\\x = \frac{-b\left \ {{+} \atop {-}}\sqrt{b^2-4.a.c}  \right. }{2.a}\\\\x = \frac{-(-7)\left \ {{+} \atop {-}}\sqrt{7^2-4.2.5}  \right. }{2.2}\\\\x = \frac{7\left \ {{+} \atop {-}}\sqrt{49-40}  \right. }{4}\\\\x = \frac{7\left \ {{+} \atop {-}}\sqrt{9}  \right. }{4}\\\\x = \frac{7\left \ {{+} \atop {-}}3\ \right. }{4}\\\\\\x_1 = \frac{10}{4}=\frac{5}{2}\\\\x_2 = \frac{4}{4}=1$