Subtract :
`cab - 4cad - cbd` from `3abc + 5bcd - cda`

Answer

To solve the problem of subtracting \( cab - 4cad - cbd \) from \( 3abc + 5bcd - cda \), we will follow these steps:

### Step 1: Write the expression for subtraction
We need to subtract \( cab - 4cad - cbd \) from \( 3abc + 5bcd - cda \). This can be expressed as:
\[ (3abc + 5bcd - cda) - (cab - 4cad - cbd) \]

### Step 2: Rewrite the expression
Rearranging the expression, we can write it as:
\[ 3abc + 5bcd - cda - cab + 4cad + cbd \]

### Step 3: Rewrite \( cda \) as \( acd \)
To maintain consistency in variable order, we can rewrite \( cda \) as \( acd \):
\[ 3abc + 5bcd - acd - cab + 4cad + cbd \]

### Step 4: Open the brackets
Now, we can combine all the terms:
\[ 3abc + 5bcd - acd - cab + 4cad + cbd \]

### Step 5: Group like terms
Now, we will group the like terms together:
- For \( abc \): \( 3abc - cab \)
- For \( bcd \): \( 5bcd + cbd \)
- For \( acd \): \( 4cad - acd \)

### Step 6: Combine like terms
Now, we can simplify each group:
1. For \( abc \):
\[ 3abc - cab = 3abc - 1abc = (3 - 1)abc = 2abc \]
2. For \( bcd \):
\[ 5bcd + cbd = 5bcd + 1bcd = (5 + 1)bcd = 6bcd \]
3. For \( acd \):
\[ 4cad - acd = 4acd - 1acd = (4 - 1)acd = 3acd \]

### Step 7: Write the final expression
Combining all the simplified terms, we have:
\[ 2abc + 6bcd + 3acd \]

### Final Answer
Thus, the result of the subtraction is:
\[ 2abc + 6bcd + 3acd \]