Veda Bites are swipeable micro-lessons — each one teaches exactly one
idea. Here's a taste from this kit; the app has the full deck.
💡 Key Idea
A pattern begging for an explanation
Three consecutive squares, one rule, and the answer is always 2.
$1 + 9 - 2(4) = 2$. And $25 + 49 - 2(36) = 2$. And so on, for ever.
↳ Replacing "it keeps happening" with "it must happen" is what this chapter does.
📖 Definition
The word every
What separates an identity from an equation?
$x + 3 = 7$ is an equation: true for one value of $x$ and false for the rest.
↳ An equation has something to solve; an identity is a tool to use.
➗ Formula
The square of a sum
The first identity, and the picture behind it.
$$(a + b)^2 = a^2 + 2ab + b^2$$
↳ With $a = 3$ and $b = 2$: $9 + 6 + 6 + 4 = 25 = 5^2$.
💡 Key Idea
Yes, and its sides are the factors
Can you lay out $x^2 + 5x + 6$ as a rectangle with no gaps?
Take one $x$ by $x$ square, five $x$ by 1 strips and six unit squares, and fit them into a single rectangle.
↳ Algebra tiles turn factorising from guesswork into building a shape.
💡 Key Idea
They do two jobs at once
Why do the numbers 2 and 3 appear in the answer?
They multiply to 6, because they form the block of six unit squares.
↳ That double role is the whole method, tiles or no tiles.
➗ Formula
Multiplying two simple brackets
The identity the picture is showing.
$$(x + a)(x + b) = x^2 + (a + b)x + ab$$
↳ The coefficient of $x$ is the sum, and the constant is the product.