Answer:
28
Step-by-step explanation:
We use the concept of similarity to find the value of X.
Δ APR ≡ ΔCDR
∴ AR/CR = PR/DR
(10+x)/x = (15+42)/42
42(10+x) = 57x
420 + 42x = 57x
57x - 42x = 420
15x = 420
x = 420/15
= 28
