# Elementary Algebra: The Algebra of Straight Lines

This is a month long unit – a four week unit design on
Elementary Algebra: The Algebra of Straight Lines.

# Overview of the unit

This unit is the second unit in this semester and will introduce you to the algebra of lines. Our journey starts with the definition of a 2D coordinate system on a plane, on which we learn to identify, name and plot points. Later we will connect the dots and draw and define lines and analyze their qualities such as straightness, slope and y-intercept. This unit is a grand bridge between single variable algebra and geometry and multi variate algebra. Thus this unit is both a natural progression from the previous unit in this semester and an important part building algebraic knowledge and skills toward the upcoming units and toward high school graduation and university level mathematics. In addition to abstract algebra, this unit is useful in practical applications such as in the field of geography, finances and engineering.

You’ll feel smarter after this unit than before taking this unit.

# Objective for the unit

By the end of this unit, the students will be able to

1. use two variables to describe a plane
2. use set-builder notation to describe sets of points
3. construct an equation for a straight line
4. change numbers in the equation to alter the position of the graph
5. use slope to represent constant rate of change
6. determine from equations whether two lines are parallel
7. use the coordinates of two points to write down an equation for a straight lineal
8. appreciate coordinate systems, plotting and lines as practical part of mathematics
9. appreciate coordinate systems, plotting and lines as practical part of real life

Here is the unit overview chart: Unit_Overview_Chart v2