A system has four processes and five different types of resources. The current allocation and maximum needs are follows:

Allocated

Process A $10211$

Process B $20111$

Process C $11010$

Process D $111110$

Maximum

$11213$

$2211$

$21310$

$11221$ value of $x$ so that DCBA is a safe sequence? In order to get credits, you should show your work clearly!