Unit 4 Test Review Chapter 6 Lessons 1-8 6-1 & 6-2 • Solve one-step equations – Do the opposite of what’s happening to the variable on both sides! – Check your answer back into the original equation – Watch your signs! – Doesn’t matter what side variable is on • Exs: Solve and check. 1.) x + 7 = -16 2.) y – 4 = -18 3.) -9x = -108 4.) 𝑛 6 = -7 • Ex: • El Rodeo School has 837 students. El Rodeo School has 78 more students than Hawthorne. How many students are there at Hawthorne School? Write an equation and then solve. • At Costco, 32 cans of Coke cost a total of $8.96. What is the cost per can? Write an equation and then solve. 6-3 • Solve one-step equations with rational coefficients – If variable is being multiplied by a decimal—divide both sides by the decimal – If variable is being multiplied by a fraction— multiply both sides by the reciprocal – Check your answer back into the original equation • Exs: Solve and check. 1.) 3.5x = 21 2.) 3 x 5 = 18 6-4 • Solve two-step equations • STEPS: 1.) 2.) 3.) 4.) 5.) 6.) Upside down T Add or subtract on both sides Upside down T Multiply or divide on both sides Answer: Variable = # (variable can be on either side) Check answer back into original equation • Exs: Solve and check. 1.) -3y – 5 = 10 2.) -7 = 2 + 𝑛 3 • How do we solve an equation that looks like this… 𝑥+7 4 = 35 • Now solve this one… 92 = 𝑥 −12 5 • How would you write a two-step equation to find the missing side length for this rectangle with a perimeter of 30 centimeters? – Solve it to find the missing side length! x 7 • What about for this triangle? – Write an equation to find the missing side lengths for the triangle below with a perimeter of 47 inches. – Solve to find the missing side lengths! • Ex: • Lou’s cell phone plan costs $39 per month. Text messages cost an additional $.15 each. If Lou’s cell phone bill last month totaled $55.05, write and solve an equation to find the number of text messages he sent. 6-5 • Multi-step equations – Has parentheses OR – Has like terms on one side OR – Has 3 or more terms on one side • *Can only start solving when you have 2 or less terms on one side and you have combined any like terms • Multi-step Equations • STEPS: 1.) Distribute if needed (keep, change, opp) 2.) Add like terms on one side of equation if needed (keep, change, opp) 3.) Add/subtract 4.) Multiply/divide 5.) Check back into original equation • Exs: Solve and check. 1.) -4 – x – 3x = 8 2.) 3(x + 4) – 8 = -8 • Solve the following equations. Round to the nearest hundredth if necessary 1.) -4(3x + 5 + 8x) = 7 • Solve the following equations. Round to the nearest hundredth if necessary 2.) 7x – 3(5x – 4) = -18 6-6 • Solve one-step addition and subtraction inequalities *Solve inequalities the same way as equations • When adding or subtracting, bring inequality sign straight down for answer • Answer: variable, inequality sign, # – *Variable must be on the left! • Ex: Solve and graph solution 1.) 17 < x + 5 2.) n – 8 ≤ -3 • Ex: A hurricane has winds that are at least 74 miles per hour. Suppose a tropical storm has winds that are 42 miles per hour. Write and solve an inequality to find how much the winds must increase before the storm becomes a hurricane. Interpret the solution. 6-7 • Solve one-step multiplication and division inequalities – If you multiply or divide by a positive number, bring inequality sign straight down. – *If you multiply or divide by a negative number, FLIP the inequality sign. • Exs: Solve and graph solution 1.) -3b ≥ -24 2.) 𝑥 12 < -3 • Ex: • T-shirts cost $18 each at the local sports store. Coach George can spend at most $162 on Tshirts for the basketball team. Write an inequality to find the number of T-shirts Coach George can buy. Interpret the solution. – Can he buy a T-shirt for all 12 members of his team? Why or why not? 6-8 • Solve 2-step inequalities • STEPS: 1.) Upside down T 2.) Add/subtract—bring sign straight down 3.) Upside down T 4.) Multiply/divide *If multiply/divide by a negative number, FLIP sign Answer: variable, inequality sign, # • Exs: Solve and graph solution 1.) 5x – 7 ≥ 43 𝑥 6 2.) 7 – > 12 • Ex: Skate Land charges a $50 flat fee for a birthday party rental and $5 per person. Joann has no more than $100 to spend on the birthday party. Write an inequality to represent the situation. Interpret the solution. How many people can Joann invite to her party?