Three patterns to recognize: (x+a)^2 = x^2 + 2ax + a^2 (sum
squared), (x-a)^2 = x^2 - 2ax + a^2 (difference squared), and
(x+a)(x-a) = x^2 - a^2 (conjugate pair / difference of squares).
Example
Apply common square and conjugate product patterns.
highlighted = computed this step
Step 1 — Set up
Set up the expression.
(x+3)2
Step 2 — Sum square
Use the sum-square pattern.
(x+3)2=x2+6x+9
Step 3 — Difference square
Use the difference-square pattern.
(x−2)2=x2−4x+4
Step 4 — Conjugates
Use the difference-of-squares pattern.
(x+4)(x−4)=x2−16
special-products
Memorize the three patterns. For conjugate pairs, the middle terms cancel. For perfect squares, the middle term is 2ax.