Calculate
1/3(1/4+7/8)

We need to find a common denominator(bottom number) for the fractions. It’s 24.
Now what do we need to multiply 3 by to get 24? 8 so you now multiply 8 by the numerator.
1 8
— x —
3 8
Because 8/8 is 1 and it’s multiplication with another fraction will not change the overall value. Just how it’s shown.
Anyway you get 8/24

How many times does 4 go into 24? 6
So...
1 6
— x —
4 6

=6/24

How many times does 8 go into 24? 3 times.

7 3
— x —
8 3

=21/24

So now the equation becomes
8/24(6/24-21/24)
6 21
— - —
24 24

You only subtract the top because the bottom is equal.
=-15/24
And then
-15 8
—- x —-
24 24
Again, multiply only the top.

You get -120/24

Then, calculate how many times 24 can fully go into 120.
5 full times with nothing left over.
But there was a negative fraction so...
You’re answer is -5