In a quadratic trinomial the constant term is positive. What must be true of the two factors of that constant?

1. A quadratic trinomial is factorised into two brackets, each holding the variable and a number. 2. The constant term of the trinomial is the product of those two numbers. 3. A positive product can only come from two numbers with the same sign. 4. So if the constant is positive, the factors must be either both positive or both negative. 5. A negative constant is the other case, where only one of the two factors is negative. 6. The middle term then decides which of the same-sign pairs is the right one. 7. Always expand the brackets again at the end to check that the middle term really works. _Source: Siyavula Mathematics Grade 10 (Everything Maths, CC BY 4.0), Chapter 1: Algebraic expressions_