Multiply a polynomial by a monomial

  1. 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.
  2. 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
  3. 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
  4. 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
  5. 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
  6. Practice with Examples:
    • Practice various examples to reinforce the concept.
    • Example: 4�⋅(2�2−3�+1)4a⋅(2a2−3a+1)
  7. 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.
  8. Check Your Answers:
    • Always check your final answer by simplifying and ensuring it makes sense in the context of the problem.
  9. Review Properties of Exponents:
    • Knowledge of exponent rules is essential for simplifying expressions when dealing with monomials and polynomials.
  10. Challenge Problems:
    • Challenge yourself with more complex problems to deepen your understanding.

Learn with an example

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.

–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.

–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!🖊️