Inequalities Ch

Equations Vs. Inequalities An equation is a number sentence that states that two expressions have the same value: X+3 = 7 means: X plus 3 is the same as 7 An inequality is a number sentence that states that one expression is greater than or less than another: X+3  7 means: X plus 3 is greater than 7

Equations Vs. Inequalities Equations will always use the equal sign, notice that both sides of the equal sign are equally large: = This makes sense since both sides of an equation are equally large.

Equations Vs. Inequalities Inequality signs have different sizes on either side: Which side of this sign is larger? The left or right? > This sign is larger on the left, so the larger value goes on the left.

Equations Vs. Inequalities

Inequalities…

You try, use the correct symbol 7  1 8  10 6  2 4  7 4     7-6

Graphs of inequalities: This is how we visually represent an inequality:

My favorite way to graph: The previous slide showed the way most texts and teachers graph, I personally prefer the following: Instead of : We can draw the graph above the number line I think this is easier for you to write and for me to read, but you can use either style.

Try this To pass a quality inspection, four random samples of a product must have a total of at least 445 quality points. Write an inequality that models this situation. Q 445 Martin got 103, 112, 115 and 120 for his four samples, write and inequality using these values and state whether Martin passed his inspection.

Try this

Try some yourself…