Answer:
CE = 17
Step-by-step explanation:
∵ m∠D = 90
∵ DK ⊥ CE
∴ m∠KDE = m∠KCD⇒Complement angles to angle CDK
In the two Δ KDE and KCD:
∵ m∠KDE = m∠KCD
∵ m∠DKE = m∠CKD
∵ DK is a common side
∴ Δ KDE is similar to ΔKCD
∴ 
∵ DE : CD = 5 : 3
∴ 
∴ KD = 5/3 KC
∵ KE = KC + 8
∵ 
∴ 
∴ 
∴ 
∴ 
∴ KC = (8 × 9) ÷ 16 = 4.5
∴ KE = 8 + 4.5 = 12.5
∴ CE = 12.5 + 4.5 = 17
 
        
             
        
        
        
Answer: He is not correct.
Steps:
Let x1 and x2 be the first and second number, respectively. 

In words, if the second is 125%, or 5/4 of the first number (first equation), 
then the first is 4/5 of the second, which is 0.8 or 80%.