The sum of two polynomials is [tex]-yz^2 - 3z^2 - 4y + 4[/tex]. If one of the polynomials is [tex]y - 4yz^2 - 3[/tex], what is the other polynomial?

A. [tex]-2yz^2 - 4y + 7[/tex]
B. [tex]-2yz^2 - 3y + 1[/tex]
C. [tex]-5yz^2 + 3z^2 - 3y + 1[/tex]
D. [tex]3yz^2 - 3z^2 - 5y + 7[/tex]



Answer :

To solve the problem, we need to find the other polynomial when given the sum of two polynomials and one of the polynomials. Let's break this down into clear, step-by-step calculations.

### Step 1: Represent the given information:
- The sum of two polynomials: [tex]\( -y z^2 - 3 z^2 - 4 y + 4 \)[/tex]
- One of the polynomials: [tex]\( y - 4 y z^2 - 3 \)[/tex]

### Step 2: Represent the unknown polynomial with a variable:
Let the unknown polynomial be [tex]\( P_{\text{unknown}}(y, z) \)[/tex].

### Step 3: Set up the equation:
According to the problem, the sum of the given polynomial and the unknown polynomial equals the provided polynomial sum:
[tex]\[ (P_{\text{unknown}}(y, z)) + (y - 4 y z^2 - 3) = -y z^2 - 3 z^2 - 4 y + 4 \][/tex]

### Step 4: Isolate the unknown polynomial:
To find the unknown polynomial, we need to isolate it on one side of the equation:

[tex]\[ P_{\text{unknown}}(y, z) = -y z^2 - 3 z^2 - 4 y + 4 - (y - 4 y z^2 - 3) \][/tex]

### Step 5: Distribute and simplify:
Now, simplify the right-hand side:
[tex]\[ P_{\text{unknown}}(y, z) = -y z^2 - 3 z^2 - 4 y + 4 - y + 4 y z^2 + 3 \][/tex]

Combine like terms:
- Combine [tex]\( -y z^2 \)[/tex] and [tex]\( 4 y z^2 \)[/tex]:
[tex]\[ -y z^2 + 4 y z^2 = 3 y z^2 \][/tex]

- Combine [tex]\( -3 z^2 \)[/tex] with no other [tex]\( z^2 \)[/tex] terms:
[tex]\[ -3 z^2 \][/tex]

- Combine [tex]\( -4 y \)[/tex] and [tex]\( -y \)[/tex]:
[tex]\[ -4 y - y = -5 y \][/tex]

- Combine [tex]\( 4 \)[/tex] and [tex]\( 3 \)[/tex]:
[tex]\[ 4 + 3 = 7 \][/tex]

Putting it all together:
[tex]\[ P_{\text{unknown}}(y, z) = 3 y z^2 - 3 z^2 - 5 y + 7 \][/tex]

### Conclusion:
The other polynomial is:

[tex]\[ \boxed{3 y z^2 - 3 z^2 - 5 y + 7} \][/tex]

This matches one of the given options.