When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. If you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

Convert Unit Rates

Direct variation is the relationship between two variables in which one is a constant multiple of the other. In other words, we can say when one variable changes the other changes in proportion to the first. If b is directly proportional to a, the equation is of the form b = ka (where k is a constant).

Direct Variation

EquARtions

The general equation of a straight line is y = mx + c, where m is the gradient, and c is the value where the line cuts the y-axis. The value of c is called the intercept on the y-axis.

Equations of a Straight Line

Fraction bARs

A linear inequality in one variable is defined as an algebraic statement that relates a linear expression (with one variable) with a constant by >, <, ≥, and ≤ sign instead of =. For example, x ≤ 5. x + 3 > − 9. a ≥ − 11.
The graph of a linear inequality in one variable is a number line in which we use open circle for < and > and a closed circle for ≤ and ≥.

Graphing Linear Inequalities in One Variable

The set of integers includes zero, negative and positive numbers without any decimal or fractional parts. To graph integers, we take a number line with 0 in the middle and place all the positive integers on the right side of 0 and all the negative integers on the left side of 0. The integers are placed at equal spaces.

Identify and Graph Integers

Mean is defined as the average of a set of numbers that can be calculated by adding all the numbers and dividing the sum by the total number of terms. Median is defined as the middle value in a given set of numbers. To find the median, list all the numbers in increasing or decreasing order. The mode is the value that occurs most frequently in a given set of numbers. Range is the difference between the lowest and highest values in a given set of numbers.

Median, Mode, Mean & Range

A parallelogram can be defined as a special quadrilateral having opposite sides equal and parallel. A diagonal of a parallelogram divides it into two congruent triangles. The sum of all the interior angles of a parallelogram is 360 degrees.