Question: formula for square minus square
1. The problem is to find the formula for the difference of squares.
2. The difference of squares formula states that for any two variables or numbers $a$ and $b$, the expression $a^2 - b^2$ can be factored.
3. The formula is:
$$a^2 - b^2 = (a - b)(a + b)$$
4. This means that the difference between the square of $a$ and the square of $b$ equals the product of the sum and difference of $a$ and $b$.
5. This formula is useful for simplifying expressions and solving equations involving squares.
6. For example, if $a=5$ and $b=3$, then:
$$5^2 - 3^2 = (5 - 3)(5 + 3) = 2 \times 8 = 16$$
7. This matches the direct calculation $25 - 9 = 16$, confirming the formula's correctness.