Basics of Algebra

Definition: Algebra involves symbols and letters to represent numbers in equations and expressions.
Variables: Symbols (often x, y, z) that represent unknown values.
Constants: Fixed values that do not change.
Expressions: Combinations of variables and constants using operations (addition, subtraction, multiplication, division).

Algebraic Expression: A combination of variables, constants, and operators (e.g., 3x + 5).
Equation: A statement that two expressions are equal (e.g., 2x + 3 = 7).
Solving Equations: Finding the value(s) of the variable that make the equation true.
- Steps: Isolate the variable, perform inverse operations, check the solution.

Polynomial: An algebraic expression with one or more terms (e.g., 4x^3 + 2x^2 - x + 7).
Terms: Individual components of a polynomial, consisting of coefficients and variables raised to powers.
Operations:
- Addition/Subtraction: Combine like terms (e.g., (2x^2 + 3x) + (4x^2 - x) = 6x^2 + 2x).
- Multiplication: Use the distributive property (e.g., (x + 2)(x + 3) = x^2 + 5x + 6).
- Division: Use long division or synthetic division for polynomials.

Linear Equation: An equation of the form ax + b = c, where a, b, and c are constants.
- Solutions: Single value of x that satisfies the equation.
Linear Inequality: An inequality that shows the relationship between expressions (e.g., ax + b > c).
- Graphing: Solutions represented on a number line or coordinate plane.

Coordinate Plane: A two-dimensional surface where points are plotted using an x and y-axis.
Graphing Linear Inequalities:
- Boundary Line: The equation of the line (e.g., y = mx + b).
- Solid vs. Dashed Line: Solid for ≤ or ≥ (inclusive), dashed for < or > (exclusive).
- Shading: Indicates the solution set (above or below the boundary line).
Solution Set: All points (x,y) that satisfy the inequality.

These notes provide a foundational understanding of key algebraic concepts relevant for first-year BSc Biotechnology students.

Algebra uses symbols and letters to represent numerical values in equations and expressions.
Variables such as x, y, z stand for unknown quantities that need to be determined.
Constants are fixed numerical values that remain unchanged within expressions.
Expressions are formed by combining variables and constants using mathematical operations like addition, subtraction, multiplication, and division.

Algebraic expressions consist of variables, constants, and operators (e.g., 3x + 5 signifies a polynomial).
An equation represents the equality of two expressions (e.g., 2x + 3 = 7).
Solving equations involves finding the value(s) of the variable that satisfy the equation.
Key steps for solving include isolating the variable, applying inverse operations, and verifying the solution.

A polynomial is an expression formed from one or more terms (e.g., 4x^3 + 2x^2 - x + 7).
Individual components of polynomials are defined as terms, which include coefficients and variables raised to powers.
Operations on polynomials include:
- Addition/Subtraction: Combine like terms, such as (2x^2 + 3x) + (4x^2 - x) equaling 6x^2 + 2x.
- Multiplication: Use the distributive property for expansion (e.g., (x + 2)(x + 3) results in x^2 + 5x + 6).
- Division: Involves long division or synthetic division techniques for polynomials.

A linear equation is structured as ax + b = c, where a, b, and c are constants.
Solutions yield a single value of x that resolves the equation.
A linear inequality expresses a non-equal relationship among variables (e.g., ax + b > c).
Solutions to inequalities can be represented graphically on a number line or in a coordinate plane.

The coordinate plane is characterized by x and y-axes that allow for point plotting.
Graphing linear inequalities involves determining the boundary line defined by the equation (e.g., y = mx + b).
Distinction between solid and dashed lines: solid lines represent inclusive inequalities (≤ or ≥), while dashed lines indicate exclusive inequalities (< or >).
Shading on the graph indicates the solution set, which represents all points (x, y) fulfilling the inequality.

Variables are symbols that stand in for unknown values, commonly represented as x or y.
Constants are numerical values that do not change, such as 5 or -3.
Operators are symbols that indicate mathematical operations, including addition (+), subtraction (-), multiplication (×), and division (÷).
Algebraic expressions are combinations of variables, constants, and operators, like 2x + 3, which can be evaluated for specific values of the variables.

An algebraic equation asserts that two expressions yield the same value, exemplified by 2x + 3 = 7.
To solve equations, isolate the variable on one side, applying inverse operations to simplify the equation accordingly.
Expressions, though they can be simplified, cannot be solved since they do not equate to a specific value, like 3x + 4y.

A polynomial consists of one or more terms, such as 4x² + 3x + 2, characterized by one or more variables raised to non-negative integer exponents.
The degree of a polynomial is determined by the highest exponent of its variable.
When performing operations on polynomials:
- Addition/Subtraction involves combining like terms, e.g., (2x² + 3x) + (x² - x) = 3x² + 2x.
- Multiplication utilizes the distributive property, as in (x + 2)(x + 3) = x² + 5x + 6.
- Division can be done through polynomial long division or synthetic division methods.

A linear equation is defined as an equation involving a first-degree polynomial, e.g., 2x + 3 = 7.
Linear equations can be represented in several forms:
- Slope-intercept form, noted as y = mx + b, where m represents the slope and b is the y-intercept.
- Standard form, expressed as Ax + By = C, where A, B, and C are constants.
Linear inequalities demonstrate relationships of greater than or less than (e.g., 2x + 3 < 7), often yielding solutions represented as ranges or intervals.

To graph linear inequalities, first graph the corresponding linear equation:
- Use a dashed line for strict inequalities (< or >) and a solid line for inclusive inequalities (≤ or ≥).
- Identify the shaded region by testing a point not on the line.
Shading convention:
- Shade above the line for "greater than" inequalities.
- Shade below the line for "less than" inequalities.
The intersection of multiple inequalities on a graph depicts the common solution set among them.