Question

Each figure represents a Real Number and no denominators are zero. Choose the
correct statement and briefly explain why the others are not correct.

A) a/b+ c/d= a+c/bd

B) a/b+c/d= a+c/b+d

C) a/b+c/d= ad+bc/bd

Answer 1

a) a/b+c/d=(a+c)/(bd)
This is incorrect (unless b=1 and d=1) because a/bd 
does not equal a/b and c/bd does not equal c/d
.
b). a/b+c/d=(a+c)/(b+d) 
This is incorrect because you cannot add fractions  merely by adding numerators and denominators.

c). a/b+c/d=(ad+bc)/(bd)
This is correct:
ad + bc/ bd = ad + bc/ bd