Home > Pre-Algebra > Inequalities > Give Solutions to Inequality

Give Solutions to Inequality

Introduction

When you solve an inequality, you get a range of solutions. If you get the equation x<8x < 8, the answer can be any number less than 8. So, dealing only with integers, the solutions are 7,6,5,4,3,2,1,0,1,2,37,6,5,4,3,2,1,0,-1,-2,-3 and so on.

To give the solutions to an inequality we need to use Interval Notation, which is a way of showing a range using only the ends of the interval.

Terms

Lesson

To give a range of solutions to an inequality, we first have to solve the equation.

If we're given:

42<x5+11-4 - 2 < x ≤ 5 + 11

We would first combine the like terms to get:

6<x16-6 < x ≤ 16

Therefore the solutions to the problem are any number greater than -6 (but not -6 itself) and any number smaller than 16 (which could include 16). In other words, the integer solutions are:

5,4,3,2,1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16

To write this out with interval notations we would set the intervals as -6 and 16. Because the solution has to be greater than, but can't equal, -6 we use the curved bracket; because it can equal 16 we use a square bracket. That gives us:

(6,16](-6, 16]

If we take another equation:

x+2<5x + 2 < 5

We would subtract 2 from both sides to isolate the x:

x+2(2)<5(2)x + 2 (-2) < 5 (-2)

x<3x < 3

So, the solutions to the equation are any numbers greater than 3 (but not 3 itself).

Since just above 3 is our lowest interval, we use a curved bracket and the number (3. The highest possible solution is infinite, so we use the infinity symbol and a square bracket ∞].

Therefore, the range of solutions is (3,∞].

Examples

Give Solutions to Inequality Worksheets (PDF)

0