How to Multiply Binomials
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The phrase "binomial," as the name implies, is made up of the terms "bi" and "nomial," which relate to a variety of expressions. A binomial is an algebraic or mathematical phrase consisting of two terms linked by a mathematical operation. Furthermore, the binomial terms may include constants, variables, or a mixed term with a co-efficient. Furthermore, the variable's power (let's say \(x\)) in a binomial should be an integer, not a fractional power like the squared or cube root.
For example, \(2x^{\frac{1}{3}} \ + \ 3x\) is not a binomial as the first term has a fraction power of \(x\).
Degree of a Binomial
Unlike a polynomial, the degree of a binomial is pretty simple to find. Since a binomial consists of only two terms, hence its degree would obviously be the greatest exponent power of that variable. So, for example in the term \(4x^3 \ + \ 3x^2\), we can see that the greatest degree of \(x\) is \(3\). So, the degree of the binomial is considered as \(3\).
Now, for a binomial expression with multiple variables, the case becomes quite complex. So, for example, let’s take the multivariable binomial expression \(3x^2y^3 \ + \ 4x^3\). Now, here we can clearly see that the binomial has 2 different variables as \(x\) and \(y\). So, what we do here is add up the exponent powers of the separate variables. So, in this case the addition comes as \(2 \ + \ 3 \ = \ 5\). Hence, the degree of this monomial is \(5\) (we do not consider the degree of \(4x^3\) i.e., \(3\) since it is lower than the multivariable term degree).
Multiplying Binomials
While multiplying binomials, take note of the following steps:
- When you are multiplying binomials, always remember the exponents rule. Multiplication always leads to addition of exponent terms of the same variables.
- Next, you should always use the distributive property while multiplying binomial.
- Next, apply the FOIL rule which is First Out Last In.
Let’s understand the multiplication of binomials by the following example:
- \((−9x \ − \ 1)(−4x \ + \ 4) \ = \ 36x^2 \ + \ (−36)x \ + \ 4x \ + \ (−4) \ = \ 36x^2 \ − \ 32x \ – \ 4\)
Free printable Worksheets
Exercises for Multiplying Binomials
1) \((-9x \ - \ 1)(-4x \ + \ 4) = \)
2) \((-9x \ - \ 8)(3x \ + \ 3) = \)
3) \((-6x \ - \ 9)(2x \ + \ 5) = \)
4) \((-5x \ - \ 4)(1x \ + \ 1) = \)
5) \((-3x \ - \ 2)(-6x \ + \ 5) = \)
6) \((-4x \ - \ 7)(5x \ + \ 4) = \)
7) \((-2x \ - \ 5)(-4x \ + \ 4) = \)
8) \((-1x \ - \ 10)(-6x \ + \ 2) = \)
9) \((-10x \ - \ 3)(-5x \ + \ 1) = \)
10) \((-7x \ - \ 6)(-2x \ + \ 2) = \)
1) \((-9x \ - \ 1)(-4x \ + \ 4) = \)\( \ \color{red}{36x^2 \ + \ (-36)x \ + \ 4x \ + \ (-4)} \)\( \ \color{red}{= \ 36x^2 \ - \ 32x \ - \ 4}\)
2) \((-9x \ - \ 8)(3x \ + \ 3) = \)\( \ \color{red}{-27x^2 \ + \ (-27)x \ + \ (-24)x \ + \ (-24)} \)\( \ \color{red}{= \ -27x^2 \ - \ 51x \ - \ 24}\)
3) \((-6x \ - \ 9)(2x \ + \ 5) = \)\( \ \color{red}{-12x^2 \ + \ (-30)x \ + \ (-18)x \ + \ (-45)} \)\( \ \color{red}{= \ -12x^2 \ - \ 48x \ - \ 45}\)
4) \((-5x \ - \ 4)(1x \ + \ 1) = \)\( \ \color{red}{-5x^2 \ + \ (-5)x \ + \ (-4)x \ + \ (-4)} \)\( \ \color{red}{= \ -5x^2 \ - \ 9x \ - \ 4}\)
5) \((-3x \ - \ 2)(-6x \ + \ 5) = \)\( \ \color{red}{18x^2 \ + \ (-15)x \ + \ 12x \ + \ (-10)} \)\( \ \color{red}{= \ 18x^2 \ - \ 3x \ - \ 10}\)
6) \((-4x \ - \ 7)(5x \ + \ 4) = \)\( \ \color{red}{-20x^2 \ + \ (-16)x \ + \ (-35)x \ + \ (-28)} \)\( \ \color{red}{= \ -20x^2 \ - \ 51x \ - \ 28}\)
7) \((-2x \ - \ 5)(-4x \ + \ 4) = \)\( \ \color{red}{8x^2 \ + \ (-8)x \ + \ 20x \ + \ (-20)} \)\( \ \color{red}{= \ 8x^2 \ + \ 12x \ - \ 20}\)
8) \((-1x \ - \ 10)(-6x \ + \ 2) = \)\( \ \color{red}{6x^2 \ + \ (-2)x \ + \ 60x \ + \ (-20)} \)\( \ \color{red}{= \ 6x^2 \ + \ 58x \ - \ 20}\)
9) \((-10x \ - \ 3)(-5x \ + \ 1) = \)\( \ \color{red}{50x^2 \ + \ (-10)x \ + \ 15x \ + \ (-3)} \)\( \ \color{red}{= \ 50x^2 \ + \ 5x \ - \ 3}\)
10) \((-7x \ - \ 6)(-2x \ + \ 2) = \)\( \ \color{red}{14x^2 \ + \ (-14)x \ + \ 12x \ + \ (-12)} \)\( \ \color{red}{= \ 14x^2 \ - \ 2x \ - \ 12}\)
Multiplying Binomials Practice Quiz