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Solving Inequalities. Algebra 1. Solving inequalities is similar to solving linear equations (ex. 2x+2=4), except for one small but important detail: you flip the inequality sign whenever you multiply or divide the inequality by a negative number. Examples -2x=4, answer: x=-2
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Solving Inequalities Algebra 1
Solving inequalities is similar to solving linear equations (ex. 2x+2=4), except for one small but important detail: you flip the inequality sign whenever you multiply or divide the inequality by a negative number. • Examples • -2x=4, answer: x=-2 • -2x≥4, answer: x≤-2
Remember: ~The opposite of addition is subtraction ~The opposite of subtraction is addition ~The opposite of multiplication is division ~The opposite of division is multiplication ~When multiplying or dividing by a negative number, the sign of the inequality switches
Please complete the following questions for homework tomorrow.
Solve. m - 3 < 6
Solve. 3 + a < 6
Solve. -2 > x - 3
Answer: x<1 ~add 3 to both sides
Solve. t + (-3) > -4
Answer: t >-1 ~Add 3 to both sides
Solve. 3 + y < -2
Answer: y<-5 ~Subtract 3 from both sides
Solve. 2x < -8
Answer: t<-4 ~Divide 2 from each side
Solve. 12 > 6k
Answer: k<2 ~Divide by 6 on both sides
Answer: a>6~Multiply by -3 on both sides, flip the inequality sign
Answer: a>-10~Multiply each side by 5, then divide each side by 2
Answer: a<-9~Multiply each side by 3, then divide each side by -2, switch the inequality sign because we are dividing by a negative number
Solve. 3x - 1 > 5
Answer: x>2~Subtract 1 from each side, then divide each side by 3
Solve. -2n + 3 < 7
Answer: n>-2Subtract 3 from each side then divide each side by a -2, switch the inequality sign because we are dividing by a negative number
Solve. 8 < 2 - 3r
Answer: r<-2~Subtract 2 from each side then divide by -3, switch the inequality sign because we are dividing by a negative number
Answer: x<-3~Subtract 1 from each side, then multiply each side by -3, switch the inequality sign because we are multiplying by a negative number
Answer: x<-7Multiply each side by 5, then subtract 2 from each side
Write an inequality: A number is greater than -3.
Write an inequality: 2 less than a number is less than 9.
Helpful Websites • http://www.youtube.com/watch?v=VgDe_D8ojxw • http://www.mathsisfun.com/algebra/inequality-solving.html • http://www.webmath.com/solverineq.html
SOL Regulations • A.5 The student will solve multistep linear inequalities in two variables, including • a) solving multistep linear inequalities algebraically and graphically; • b) justifying steps used in solving inequalities, using axioms of inequality and • properties of order that are valid for the set of real numbers and its subsets; • c) solving real-world problems involving inequalities; and • d) solving systems of inequalities.