Inequalities
By the end of this lesson you will be able to:
• Read and represent inequalities.
• Solve inequalities algebraically.
inequalities
n is less than 3
x is greater than or equal to 8
a is less than or equal to 5
n < 3
x ≥ 8
a ≤ ‐5
is equivalent to
x is greater than 3 but less than 8
a is greater than 4 but less than or equal to 9
3 < 6
3 < x < 8
‐4 < a ≤ 9
6 > 3
Represent the inequalities on the number line.
Represent the inequalities on the number line.
+ 7 + 7
In an inequality , you can add he same number to both sides and the inequality remains true.
In an inequality , you can subtract the same number to both sides and the inequality remains true.
‐3 ‐3
In an inequality , you can multiply by the same positive number both sides and the inequality remains true.
x3 x 3
In an inequality , you can divide by the same positive number both sides and the inequality remains true.
÷2 ÷2
What happens if you multiply the inequality by a negative number ?
x (‐1) x (‐1)
What happens if you divide the inequality by a negative number ?
÷ (‐2) ÷ (‐2)
When you multiply or divide an inequality by a negative number, the sign must be changed around.
Solve the inequality and represent the solution on a number line.
15 + 3 x < 6
Solve the inequality and represent the solution on a number line.
18 ≤ 7x + 4
Solve the inequality and represent the solution on a number line.
19 4 x ≥ 3
Solve the inequality and represent the solution on a number line.
4 5 x ≥ 2x 3
3 ( x 1 ) < 2 ( 1 x )
2( x 1 ) > x 7
Solve from Book : pages 62 & 63