Notes, solutions of unit 08, General Mathematics 9, for Punjab Curriculum & Textbook Board (PCTB), Lahore.

* Identify pair of real numbers as an ordered pair.

• Recognize an ordered pair through different examples.
• Describe rectangular or Cartesian plane consisting of two number lines interesting at right angles at the point $O$.
• Identify origin $(O)$ and coordinate axes (horizontal and vertical axes or $x-axis$ and $y-axis$) in the rectangular plane.
• Locate an ordered pair $(a, b)$ as a point in the rectangular plane and recognize.
• $a$ as the $x$-coordinate (or abscissa),
• $b$ as the $y$-coordinate (or ordinate).
• Draw different geometrical shapes (e.g., line segment, triangle and rectangle etc.) by joining a set of given points.
• Construct a table for pairs of values satisfying a linear equation in two variables.
• Plot the pairs of points to obtain the graph of a given expression.
• Choose an appropriate scale to draw a graph.
• Draw a graph of
• an equation of the form $y = c$,
• an equation of the form $x = a$,
• an equation of the form $y = mx$,
• an equation of the form $y = mx + c$.
• Draw a graph from a given table of (discrete) values.
• Solve appropriate real life problems.
• Interpret conversion graph as a linear graph relating to two quantities which are in direct proportion.
• Read a given graph to know one quantity corresponding to another.
• Read the graph for conversions of the form.
• miles and kilometers, acres and hectares,
• degrees Celsius and degrees Fahrenheit,
• Pakistani currency and another currency, etc.
• Solve simultaneous linear equations in two variables using graphical method.