Answer :

Let's simplify the given expression step by step:

Given expression:
[tex]\[ 4 - 5x^2 - 3y^3 + 7y^3 - 5 + 1 - y^3 \][/tex]

1. Combine like terms:
First, let's identify and combine the constants and the terms involving [tex]\( y^3 \)[/tex].

- The constants are: [tex]\( 4 - 5 + 1 \)[/tex].
- The terms involving [tex]\( y^3 \)[/tex] are: [tex]\( -3y^3 + 7y^3 - y^3 \)[/tex].

2. Simplify the constants:
[tex]\[ 4 - 5 + 1 = 0 \][/tex]

3. Simplify the terms involving [tex]\( y^3 \)[/tex]:
[tex]\[ -3y^3 + 7y^3 - y^3 = (7 - 3 - 1)y^3 = 3y^3 \][/tex]

4. Combine the [tex]\(x^2\)[/tex] term with itself, if any:
The term involving [tex]\( x^2 \)[/tex] is simply [tex]\(-5x^2\)[/tex], and it remains unchanged.

After combining all like terms, the simplified expression is:
[tex]\[ -5x^2 + 3y^3 \][/tex]

Therefore, the result is:
[tex]\[ -5x^2 + 3y^3 \][/tex]