Resposta :
a) 5/4 + 3/6 -> 5/4 + 1/2
mmc de 4 e 2 = 4
5/4 + 1×2/2×2
5/4 + 2/4
5 + 2/4
= 7/4
[tex]\frac{ 5 }{ 4 } + \frac{ 3 }{ 6 } \\ \\\frac{5}{4}+\frac{1}{2} \\ \\ \frac{5}{4}+\frac{2}{4} \\ \\ \frac{5+2}{4} \\ \\ \frac{7}{4} \\ \\ espero \: ter \: ajudado!![/tex]