Watch Video on Solving Inequalities – Algebra Help
Monday, December 14th, 2009
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/solvinginequalities.php Students learn that when solving an inequality, such as –3x is less than 12, the goal is the same as when solving an equation: to get the variable by itself on one side. Note that when multiplying or dividing both sides of an inequality by a negative number, the direction of the inequality sign must be switched. For example, to solve –3x is less than 12, divide both sides by –3, to get x is greater than -4. And when graphing an inequality on a number line, less than or greater than means an open dot, and less than or equal to or greater than or equal to means a closed dot.
Duration : 0:2:52
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/graphinglinearinequalities.php Students learn to graph inequalities in two variables. For example, to graph y is less than x + 2, the first step is to graph the boundary line y = x + 2, using the chart method from lesson 4B. Note that greater than or less than means that the boundary line will be dotted, and greater than or equal to or less than or equal to means that the boundary line will be solid. To determine which side of the boundary line to shade, substitute a test point, such as (0, 0), into the original inequality, y is less than x + 2. Since (0) is less than (0) + 2, or 0 is less than 2, is a true statement, the side of the line that contains the point (0, 0) is shaded.