15. The Distributive Property
𝒙 + 𝟐 𝟐𝒙 + 𝟑
𝒙 𝟐𝒙 + 𝟑 + 𝟐(𝟐𝒙 + 𝟑)
𝟐𝒙 𝟐
+ 𝟑𝒙 + 𝟒𝒙 + 𝟔
𝟐𝒙 𝟐
+ 𝟕𝒙 + 𝟔
NOTE: Since there are THREE terms,
this is called a TRINOMIAL.
17. Multiplying MOST binomials results in
THREE terms
TRINOMIALS
You can learn to
multiply binomials in
your head by using a
method called
F O I L
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
18. The FOIL method is ONLY used when you
multiply two (2) binomials.
It is an acronym and tells you which terms to
multiply.
FOIL
Use the FOIL method
to multiply the
following binomials:
(𝑦 + 4)(𝑦 + 5)
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
19. F tells you to multiply the FIRST
terms of each binomial.
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
(𝒚 + 𝟒)(𝒚 + 𝟓)
𝒚 𝟐
20. O tells you to multiply the OUTER
terms of each binomial.
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
(𝒚 + 𝟒)(𝒚 + 𝟓)
𝒚 𝟐
+ 𝟓𝒚
21. I tells you to multiply the INNER
terms of each binomial.
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
(𝒚 + 𝟒)(𝒚 + 𝟓)
𝒚 𝟐
+ 𝟓𝒚 + 𝟒𝒚
22. L tells you to multiply the LAST
terms of each binomial.
MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
(𝒚 + 𝟒)(𝒚 + 𝟓)
𝒚 𝟐
+ 𝟓𝒚 + 𝟒𝒚 + 𝟐𝟎
23. MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
(𝒚 + 𝟒)(𝒚 + 𝟓)
𝒚 𝟐
+ 𝟓𝒚 + 𝟒𝒚 + 𝟐𝟎
Combine LIKE terms.
𝒚 𝟐
+ 𝟓𝒚 + 𝟒𝒚 + 𝟐𝟎
𝒚 𝟐
+ 𝟗𝒚 + 𝟐𝟎
24. FOIL reminds you to
multiply the:
First terms
Outer terms
Inner terms
Last terms
REMEMBER…
26. MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
The 2nd method is the BOX method. This
method works for every problem!
Here’s how you do it:
(𝟒𝒙– 𝟑)(𝟐𝒙 + 𝟓)
Draw a box. Write a polynomial on
the top & side of a box.
It does not matter where.
This will be modeled in the next
problem along with FOIL.
𝟒𝒙 −𝟑
𝟐𝒙
+𝟓
27. MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
Multiply (𝟒𝒙 − 𝟑)(𝟐𝒙 + 𝟓)
First terms:
Outer terms:
Inner terms:
Last terms:
Combine like terms.
𝟖𝒙 𝟐 + 𝟏𝟒𝒙– 𝟏𝟓
4𝒙 −𝟑
2𝒙
+5
𝟖𝒙 𝟐
+𝟐𝟎𝒙
−𝟔𝒙
−𝟏𝟓
You have 2 techniques. Pick the one you like the best!
𝟖𝒙 𝟐
+𝟐𝟎𝒙
−𝟔𝒙
−𝟏𝟓
28. MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
Multiply (𝟕𝒂 + 𝟓)(𝟑𝒂 − 𝟏)
First terms:
Outer terms:
Inner terms:
Last terms:
Combine like terms.
𝟐𝟏𝒂 𝟐 + 𝟖𝒂 − 𝟓
𝟕𝒂 +𝟓
𝟑𝒂
−𝟏
𝟐𝟏𝒂 𝟐
−𝟕𝒂
+𝟏𝟓𝒂
−𝟓
𝟐𝟏𝒂 𝟐
−𝟕𝒂
+𝟏𝟓𝒂
−𝟓
29. MATHEMATICS 8 (PATTERNS AND ALGEBRA 1st Quarter) MR. CARLO JUSTINO J. LUNA
Multiply (𝟐𝒎 + 𝒏)(𝟒𝒎 + 𝟐𝒏)
First terms:
Outer terms:
Inner terms:
Last terms:
Combine like terms.
𝟖𝒎 𝟐 + 𝟖𝒎𝒏 + 𝟐𝒏 𝟐
𝟐𝒎 +𝒏
𝟒𝒎
+𝟐𝒏
𝟖𝒎 𝟐
𝟒𝒎𝒏
𝟒𝒎𝒏
𝟐𝒏 𝟐
𝟖𝒎 𝟐
+𝟒𝒎𝒏
+𝟒𝒎𝒏
𝟐𝒏 𝟐