Class XI

Solve one, two or three step inequalities

Lesson

When we solve inequalities, we are trying to work out what range of values makes the inequality true. One difference in solving these inequalities is that an equals symbol has been replaced by an inequality symbol.

Another difference is that, in an equation such as $x-1=5$x−1=5, only one value of $x$x satisfies the equation. In an inequality such as $x-1>5$x−1>5, there will be many $x$x values that satisfy the inequality.

To solve one-step inequalities, we follow a similar process to one step equations.

Remember

When you multiply or divide by a negative number you have to reverse the inequality sign.

e.g. $-x>3$−x>3 would become $x<-3$x<−3.

Examples

QUESTION 1

Solve the following inequality: $x+5>14$x+5>14

Question 2

Solve the following inequality: $10x<90$10x<90

Question 3

Solve the following inequality: $3x+27>3$3x+27>3

Question 4

Solve the following inequality: $4\left(2x+3\right)>-4$4(2x+3)>−4

Question 5

Solve the following inequality: $2\left(8-\frac{x}{3}\right)\ge14$2(8−x3)≥14 .

Outcomes

11.A.LE.1

Linear inequalities. Algebraic solutions of linear inequalities in one variable and their representation on the number line. Graphical solution of linear inequalities in two variables. Solution of system of linear inequalities in two variables – graphically.