Lesson 16
Working with Quadratics
- Let’s explore terms in a quadratic equation.
16.1: Order of Operations and Roots
Find the value of these expressions.
- \(\sqrt{9}+2\)
- \(\frac{\sqrt{16}}{2}\)
- \((\sqrt{25})^2+6.2)\)
- \((\frac{\sqrt{100}}{4} - \frac{\sqrt{64}}{2})\)
- \(\sqrt{1+ 15}\)
- \(\sqrt{4^2 + 3^2}\)
16.2: Finding Coefficients
Rewrite the equation in standard form \(ax^2 + bx + c = 0\), then identify \(a, b,\) and \(c\). Then compute \(b^2 - 4ac\).
- \(x^2 - 3x + 5 = 0\)
- \(3x^2 - 4 + x = 0\)
- \(\text{-}2x^2 + 5x = 11\)
- \(3x^2 + 5x = 9 - 4x\)
- \(\frac{2x^2}{3} + 6x -13 = 13\)
- \(x^2 - 9 = 0\)
- \(9+x-4x^2 = 1\)
- \((x+2)(x-3) = 0\)
16.3: Practicing Methods for Solving Quadratic Equations
Solve each of these quadratic equations by either rewriting the expression in factored form or completing the square. Explain or show your reasoning for the method you choose to use.
- \(x^2 - 3x - 4 = 0\)
- \(x^2 + x = 6\)
- \(x^2 + 6x + 7 = 5\)
- \(x^2 +12 = 7x\)
- \(x^2 + 3x - 5 = 0\)