Question: Fully factorise $2x^2 - 13x + 15$
1. **State the problem:** Fully factorise the quadratic expression $$2x^2 - 13x + 15$$.
2. **Recall the factoring formula:** For a quadratic $$ax^2 + bx + c$$, we look for two numbers that multiply to $$a \times c$$ and add to $$b$$.
3. **Calculate the product and sum:** Here, $$a = 2$$, $$b = -13$$, and $$c = 15$$.
Calculate $$a \times c = 2 \times 15 = 30$$.
We need two numbers that multiply to $$30$$ and add to $$-13$$.
4. **Find the pair:** The numbers are $$-10$$ and $$-3$$ because $$-10 \times -3 = 30$$ and $$-10 + (-3) = -13$$.
5. **Rewrite the middle term:**
$$2x^2 - 10x - 3x + 15$$
6. **Group terms:**
$$(2x^2 - 10x) + (-3x + 15)$$
7. **Factor each group:**
$$2x(x - 5) - 3(x - 5)$$
8. **Factor out the common binomial:**
$$(2x - 3)(x - 5)$$
9. **Final answer:** The fully factorised form of $$2x^2 - 13x + 15$$ is $$\boxed{(2x - 3)(x - 5)}$$.