Question 1014514
You need common denominators to solve this. So, what number do 2 and 4 share? 
The number is "4"

{{{1/2}}} + {{{(-3/4)}}}

{{{1/2}}} = {{{x/4}}}
Since the "2" was multiplied by 2 to get 4, we do the same thing to the numerator, which is to multiply it by 2 as well.

{{{1/2}}} = {{{2/4}}}

Now, you can add the two fractions.

{{{2/4}}} + {{{(-3/4)}}}
answer {{{-1/4}}}