Resposta:

[tex]\Large \textsf{Leia abaixo}[/tex]

Explicação passo a passo:

[tex]\Large \boxed{\text{$\sf Taxa\:juros\:real = \dfrac{1 + Taxa\:de\:juros\:nominal}{1 + Taxa\:de\:inflac{\~a}o} - 1$}}[/tex]

[tex]\Large \text{$\sf Taxa\:juros\:real = \dfrac{1 + 0,40}{1 + 0,30} - 1$}[/tex]

[tex]\Large \text{$\sf Taxa\:juros\:real = \dfrac{1,40}{1,30} - 1$}[/tex]

[tex]\Large \text{$\sf Taxa\:juros\:real = 1,07692 - 1$}[/tex]

[tex]\Large \text{$\sf Taxa\:juros\:real = 0,07692$}[/tex]

[tex]\Large \boxed{\boxed{\text{$\sf Taxa\:juros\:real = 7,69\%$}}}[/tex]