The Lowest Common denominator of 5 and 12 is 60. So you have to bring each fraction up to 60
[tex] \dfrac{7}{12}=\dfrac{7*5}{12*5} =\dfrac{35}{60} [/tex]
[tex] \dfrac{10}{5} = \dfrac{10*12}{5*12} = \dfrac{120}{60} [/tex]
[tex] \dfrac{35}{60}+\dfrac{120}{60}=\dfrac{155}{60}=\dfrac{35}{12}[/tex]
which can be written as 2 11/12