Answer :

To simplify the algebraic expression [tex]\( 10y - 3(y + 5) \)[/tex] completely, follow these steps:

1. Distribute the [tex]\(-3\)[/tex] through the terms inside the parentheses:
[tex]\[ 10y - 3(y + 5) = 10y - 3y - 3 \times 5 \][/tex]

2. Multiply the constants:
[tex]\[ 10y - 3y - 15 \][/tex]

3. Combine like terms (the terms involving [tex]\( y \)[/tex]):
[tex]\[ 10y - 3y = 7y \][/tex]

4. Finally, put the simplified terms together:
[tex]\[ 7y - 15 \][/tex]

So, the simplified expression is:
[tex]\[ 7y - 15 \][/tex]

Therefore, the correct answer is:

B. [tex]\( 7y - 15 \)[/tex]