Which pair of expressions is equivalent for any variable value greater than zero?

Answer:
D. b+b+3c and 2b+3c
Step-by-step explanation:
The question wants us to find out expressions is equivalent for any variable value greater than zero. So let's analyse all the possible answers to find the correct one.
A. (x+3) and 3x+ 2
If x = 1 , we have:
Both of the two sides are not equivalent
B. 4d+2e and 8d+e
If e=1 and d=1, we have:
Both of the two sides are not equivalent
C. f+f+f+g and 3fg
If f=1 and g=1, we have:
Both of the two sides are not equivalent
D. b+b+3c and 2b+3c
If b=1 and c=1, we have:
Both of the two sides are equivalent
Or we will simplify the left side: b+b+3c = 2b+3c, hence 2b+3c = 2b+3c are apparent
So we choose D.