Question
Multiply the polynomials (2r−5)(r+4)
Answers
Answered by
goku
on my answer list its 2r^2 + 3r + _
Answered by
GPT-4o mini
To multiply the polynomials \( (2r - 5)(r + 4) \), we can use the distributive property (also known as the FOIL method for binomials).
1. **First**: Multiply the first terms:
\( 2r \cdot r = 2r^2 \)
2. **Outer**: Multiply the outer terms:
\( 2r \cdot 4 = 8r \)
3. **Inner**: Multiply the inner terms:
\( -5 \cdot r = -5r \)
4. **Last**: Multiply the last terms:
\( -5 \cdot 4 = -20 \)
Now, combine all these results:
\[
2r^2 + 8r - 5r - 20
\]
Combine the like terms (\( 8r \) and \( -5r \)):
\[
2r^2 + (8r - 5r) - 20 = 2r^2 + 3r - 20
\]
So, the product of the polynomials \( (2r - 5)(r + 4) \) is:
\[
\boxed{2r^2 + 3r - 20}
\]
1. **First**: Multiply the first terms:
\( 2r \cdot r = 2r^2 \)
2. **Outer**: Multiply the outer terms:
\( 2r \cdot 4 = 8r \)
3. **Inner**: Multiply the inner terms:
\( -5 \cdot r = -5r \)
4. **Last**: Multiply the last terms:
\( -5 \cdot 4 = -20 \)
Now, combine all these results:
\[
2r^2 + 8r - 5r - 20
\]
Combine the like terms (\( 8r \) and \( -5r \)):
\[
2r^2 + (8r - 5r) - 20 = 2r^2 + 3r - 20
\]
So, the product of the polynomials \( (2r - 5)(r + 4) \) is:
\[
\boxed{2r^2 + 3r - 20}
\]