Inequalities are like equations except that in the place
of = we use <,>, ≤, or ≥ .
Treat inequalities exactly as you treat equations , with one important exception. If you multiply the inequality by a negative number, then you must reverse the inequality.
Part 1 Graphing inequalities .
The graph will be done on the board.
Question 3 Graph
Question 4 Graph
x < 4
Question 12 Solve and Graph
Subtract 5 from both sides
Part 2 Solving inequalities
Question 18: Solve
Subtract 8 from both sides x≥−22
Question 42: Solve
Subtract 2.8x from both sides x < −3.8
Question 59: Solve −8x ≤ −40
Divide both sides by −8 : [Remember that since we are multiplying/dividing by a negative number that we must reverse the inequality.] x≥5
Question 93: Solve 0.07x < −0.378
Divide by 0.07
So the solution is x < −5.4
Collect ( Combine ) like terms on each side
Subtract 6y from both sides: 10−10y≤−20
Subtract 10 from both sides: −10y≤−30
Divide both sides by −10 . Reverse the inequality.
Question 134: Use the roster method to list the set of positive integers that are solutions of the inequality 13−8a≥2−6a
First we solve the inequality :
Add 8a to both sides:
Subtract 2. 11≥2a
Divide by 2 .
Roster method gives us
because , we can’t go any higher than 5.