5.5. Inequalities Flashcards
x < 4
means ‘x is less than 4’
y > 7
means ‘x is greater than 7’
z ≤ 10
means ‘z is less than OR equal to 10
t ≥ 3
means ‘t is greater than OR equal to 3
What happens when you multiply an inequality by a negative number?
The inequality is reversed
4 > -2
multiply by negative two
-8 < 4
Solve
2x - 1 > 5
2x - 1 > 5
2x > 6
x > 3
Solve
5 - 3x ≤ 1
5 - 3x ≤ 1
-3x ≤ -4
x ≥ 1.3333
What does ‘o’ represent on an inequality line?
< or >
What does ‘●’ represent on an inequality line?
≤ or ≥
Representing x < 2 on a graph
A dashed line at x = 2, where an area greater than x = 2 is shaded…
The line is dashes because it doesn’t include 2.
The unwanted region is always shaded.
Representing x ≤ 2 on a graph
A straight line at x = 2
It is straight (not dashed) because it includes 2.
The shaded area is the area in which x couldn’t be (aka any coordinate where x is not greater or equal to x)
The unwanted region is always shaded.
