Algebra 1 formulas

Quadratic Formula

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$ - Used to find the roots of a quadratic equation.

Slope-Intercept Form

$$y = mx + b$$

Exponential growth

y=a(1+r^t

Exponential decay

y=a(1+r)^t

Standard Form of a Linear Equation

$Ax + By = C$ - Represents a linear equation where A, B, and C are integers.

Difference of Squares

$a^2 - b^2 = (a + b)(a - b)$ - A formula for factoring the difference between two squares.

Factoring a Quadratic

$ax^2 + bx + c = (mx + n)(px + q)$ - Used to factor quadratic expressions.

Area of a Rectangle

$A = l \times w$ - The area is the length multiplied by the width.

Pythagorean Theorem

$a^2 + b^2 = c^2$ - Relates the lengths of the sides of a right triangle.

Sum of Angles in a Triangle

$A + B + C = 180^ ext{o}$ - The sum of the interior angles of a triangle.

Arithmetic sequence

an=a1+(n-1)d

Geometric sequence(multiplying)

Explicit formula: an = a1 x r^n-1

Geometric sequence (recursive formula)

An=an-1 x r