ZONK Review 1. Find the solution to the following system of equations by graphing: 2. Graph the system of inequalities and name three points in the solution set. −4𝑥 + 𝑦 = −5 𝑦 = 4𝑥 + 3 𝑥≤2 6𝑥 − 3𝑦 < 12 Change the first equation to y = 4x – 5. x – int: 6x = 12 x=2 y – int: -3y = 12 y = -4 Then graph using y = mx + b. Example Points: (-1, 0) (-2, 2) (-4, 5) NO SOLUTION 3. Solve the following system using SUBSTITUTION. 4. Solve the following system using ELIMINATION. 6x – 5y = 76 -3x + 5y = -43 −2𝑥 + 6𝑦 = −8 9 𝑥 = 2𝑦 + 3 9 9 2 −2 (2 𝑦 + 3) + 6𝑦 = −8 𝑥 = 2 (3) + 3 3x + 0 = 33 -9y – 6 + 6y = -8 -3y – 6 = -8 -3y = -2 2 𝑦=3 𝑥 = 6 +3 x=3+3 x=6 x = 11 18 𝟐 (6, 𝟑) Add Equations 6(11) – 5y = 76 66 – 5y = 76 - 5y = 10 y = -2 (11, -2) 5. There are 400 turtles competing in the Turtle Grand Prix. It cost each turtle $20 to register for the 5k race and $35 to register for the 10k race. If the Turtle Grand Prix brought in $10,340 in registration fees, how many turtles ran each distance? f – # of turtles in the five K race t - # of turtles in the ten K race 20f + 35t = 10, 340 f + t = 400 - t = -t So f = 400 – t USE SUBSTITUTION 20(400 – t) + 35t = 10,340 8,000 – 20t + 35t = 10,340 8,000 + 15t = 10,340 15t = 2,340 t = 156 f = 400 – (156) = 244 244 registered for the 5K and 156 registered for the 10K. 6. Turtles who signed up for the annual Turtle Grand Prix for the very first time received three free T-shirts. Those turtles who were returning runners only received one free t-shirt. The difference between the number of first time runners at the 5k and the number of returning runners was 60. If they gave away a total of 548 free t-shirts, how many turtles were first time runners? f - # of first time runners r - # of returning runners 3f + 1r = 548 f - r = 60 +r=+r So f = 60 + r. USE SUBSTITUTION 3(60 + r) + r = 548 180 + 3r + r = 548 180 + 4r = 548 4r = 368 r = 92 152 first time runners 92 returning runners f = 60 + 92 = 152 7. Solve the following system using SUBSTITUTION. 8. Solve the following system using ELIMINATION. 3x + y = 8 so y = -3x + 8 4x + 6y = 6 4x + 6(-3x + 8) = 6 y = -3(3) + 8 4x – 18x + 48 = 6 y = -9 + 8 -14x + 48 = 6 y = -1 -14x = - 42 x=3 (3, -1) (-3x + 3y = 12) ∙ 4 (4x + 2y = 20) ∙ 3 -12x + 12y = 48 12x + 6y = 60____ 18y = 108 y=6 -3x + 3(6) = 12 -3x + 18 = 12 -3x = -6 x=2 (2, 6) 9. Spectators at the Turtle Grand Prix can purchase Turtle Trax Ice Cream Cones at the concession stand. The difference between the price of the waffle cone and the price of the regular cone is $0.75. If a family of seven purchased three waffle cones and four regular cones for a total of $28.50, how much was the cost of a single waffle cone? w - price of a waffle cone. r – price of a regular cone. Use elimination to eliminate the r because you only need to find the price of the waffle cone. (w – r = .75) ∙ 4 3w + 4r = 28.50 4w – 4r = 3____ 7w = 31.50 w = $4.50 10. Find the solution to the following system of equations by graphing: 1 4 1 𝑥 + 4 𝑦 = −1 3𝑦 = 𝑥 (-3, -1) A single waffle cone is $4.50 11. Graph the system of inequalities and name three points in the solution set. 3 −𝑥 + 2 𝑦 > −3 𝑦 ≤ −𝑥 Ex Points: (-2, 0) (-3, 1) (-4, 2) Directions: Solve the following systems using SUBSTITUTION OR ELIMINATION. 12. 3x + 4y = 9 4y – 3x = -1 Line up the x’s and y’s! 3x + 4y = 9 -3x + 4y = -1 8y = 8 y=1 3x + 4(1) = 9 3x + 4 = 9 𝟓 ( ,1) 13. (3x + 4y = 2) ∙ -3 9x + 12y = 6 -9x – 12y = -6 0+0=0 Infinitely Many Solutions 3x = 5 𝟑 5 x=3 14. Tammy Turtle is going to the concession stand with 11 coins that total exactly $2.00. If her coins are all quarters and dimes, how many of each coin does she have? q = # of quarters d = # of dimes Use Elimination (q + d = 11) ∙ -.25 .25q + .1d = 2.00 -.25q - .25d = -2.75 -.15d = -.27 d=5 q + 5 = 11 q=6 5 dimes and 6 quarters 15. The race is on! Tony the Turtle got a good start. He has already gone 11 feet, and he is currently traveling at a rate of three feet per minute. Tammy the Turtle woke up late and is just now starting the race, but she’s determine to catch up and is traveling at a rate of 3.5 feet per minute. How many minutes will it take for Tammy to Catch up to Tony? How far will they have traveled at that time? Let m = # of minutes And d = distance traveled Tony: Tammy: d = 3m + 11 d = 3.5m Substitution: 3.5m = 3m + 11 .5m = 11 m = 22 d = 3.5(22) = 77 They will have both gone 77 feet after 22 minutes.