I Believe it would be 53 because it’s asking what is the difference and they difference would have to be 53 your going from a negative to a positive

+ 3x + 5
-

+ 6x + 5
-----------------------------------------
4x - 3 + 0
20( -1.5r + 0.75)
Multiply everything by 20
= -30r + 15
If the 1m turns into 3m then he cm increases also by 3.The 3 meters would equal 300 cm.