Answer:
The value of b is, 8
Step-by-step explanation:
To determine the value of b:
Given:
....[1]
Since, 0x6A represents the hexadecimal form.
To convert this hexadecimal form into decimal form:

⇒
(decimal form)
Now we have to convert this decimal form into octal
8 | 106
8 | 13 | 2
| 1 | 5
1
Then, the octal form we get, 
Substitute this in [1] we have;

On comparing both sides we have;
b = 8
Therefore, the value of b is, 8
First do 6×8=48, then just add the 0's to the end to get 480,000
We want 4/5 of a number to be 144. This means that

Multiplying both sides by 5/4, we have

Answer:
solution given:
balanced: C4H6O3 + H2O −−→2 C2H4O2