The first thing you should know is that there are many ways to solve this problem.
One of the ways, for example, is a simple addition of fractions.
We have then:
Step 1:
Cross product
3/4 + 1/8 = ((3 * 8) + (1 * 4)) / (4 * 8)
Step 2:
Rewrite
((3 * 8) + (1 * 4)) / (4 * 8) = (24 + 4) / (32) = 28/32
Step 3:
simplify
28/32 = 14/16 = 7/8
Answer:
Step 1:
Cross product
3/4 + 1/8 = ((3 * 8) + (1 * 4)) / (4 * 8)