Multiply a polynomial by a monomial
key notes:
- Definition:
- A polynomial is an expression consisting of variables and coefficients, combined using addition, subtraction, and multiplication.
- A monomial is a polynomial with only one term.
- Multiplying a Monomial by a Polynomial:
- To multiply a monomial by a polynomial, distribute each term of the monomial to every term in the polynomial.
- Example: 3�⋅(2�2+5�−1)3x⋅(2x2+5x−1)
- Distribute 3x to each term: 3�⋅2�2+3�⋅5�−3�⋅13x⋅2x2+3x⋅5x−3x⋅1
- Multiplication Rules:
- Multiply coefficients together.
- Add exponents when the base (variable) is the same.
- Example: 2�3⋅4�2=8�3+2=8�52x3⋅4x2=8x3+2=8x5
- Combining Like Terms:
- After multiplying, combine like terms by adding or subtracting coefficients.
- Example: 3�⋅2�2+3�⋅5�−3�⋅13x⋅2x2+3x⋅5x−3x⋅1
- Combine like terms: 6�3+15�2−3�6x3+15x2−3x
- Example: 3�⋅2�2+3�⋅5�−3�⋅13x⋅2x2+3x⋅5x−3x⋅1
- After multiplying, combine like terms by adding or subtracting coefficients.
- Be Mindful of Signs:
- Pay attention to the signs when distributing the monomial.
- Example: (−2�)⋅(3�2−4�+1)(−2y)⋅(3y2−4y+1)
- Distribute −2�−2y: −2�⋅3�2+(−2�)⋅(−4�)+(−2�)⋅1−2y⋅3y2+(−2y)⋅(−4y)+(−2y)⋅1
- Practice with Examples:
- Practice various examples to reinforce the concept.
- Example: 4�⋅(2�2−3�+1)4a⋅(2a2−3a+1)
- Real-Life Applications:
- Understanding how to multiply polynomials by monomials is useful in algebraic expressions and equations, which are common in various real-life scenarios.
- Check Your Answers:
- Always check your final answer by simplifying and ensuring it makes sense in the context of the problem.
- Review Properties of Exponents:
- Knowledge of exponent rules is essential for simplifying expressions when dealing with monomials and polynomials.
- Challenge Problems:
- Challenge yourself with more complex problems to deepen your understanding.
Learn with an example
➡️ Find the product.
Simplify your answer
r.–3(–q2 + 2)
Find the product.
–3 (–q2 + 2)
–3 (–q2) + –3(2) Apply the distributive property
3q2+–6 Simplify
3q2–6 Rewrite as subtraction
➡️ Find the product.
Simplify your answer.
–9(2z2–7)
Find the product.
–9(2z2–7)
–9(2z2+–7) Rewrite as addition
–9(2z2)+–9(–7) Apply the distributive property
–18z2+63 Simplify
➡️ Find the product.
Simplify your answer.
–3k (k2–4k)
Find the product.
–3k (k2–4k)
–3k (k2+–4k) Rewrite as addition
–3k (k2) + –3k (–4k) Apply the distributive property
– 3k3+12k2 Simplify
let’s practice!🖊️