2-4 Solving equations with variables on both sides Goals: Collect variables on one side of an equation Use equations to solve real-life problems Eligible Content: A1.1.2.1.1 / A1.1.2.1.2 / A1.1.2.1.3
Collect variables on one side of = Decide which variable you want to move. Add or subtract it from both sides to cancel it out. Solve equation just like we did yesterday!
7x + 19 = -2x + 55 +2x +2x 9x + 19 = 55 - 19 - 19 9x = 36 9 9 x = 4
examples 6x + 22 = -3x + 31 90 – 9y = 6y 72 – 12w = 6w x = 1 y = 6 w = 4 x = -2 x = 5
Solve 9f – 6 = 3f + 7. A. B. C. D. 2
Vocabulary No Solution – there is no value that works for the equation. This is the answer if you get all variables to cancel out and you are left with a false statement. 2 = 8 All Real Numbers– any value works for the equation. This is the answer if you get all variables to cancel out and you are left with a true statement. 3 = 3
Tricky problems 3x + 6 = 3x + 4 5x + 8 = 5x + 8 No solution All real numbers
practice Worksheet – “2-4 Solving Equations with Variables on Both Sides”
Word problem #1 A video store charges $8 to rent a video game for five days. You must be a member to rent from the store, but the membership is free. A video game club in town charges only $3 to rent a game for five days, but membership in the club is $50 per year. How many games would you have to rent for the price to be the same? 8x = 3x + 50 x = 10 games
Word problem #2 A gym offers two packages for yearly membership. The first plan costs $50 to be a member. Then each visit to the gym is $5. The second plan costs $200 for a membership fee plus $2 per visit. How many times do you have to visit the gym for the cost to be the same? 50 + 5x = 200 + 2x x = 50 visits
homework Pages 100-101 #1-2, 10-13, 38-40 Get your Notebook Grade Sheet signed by a parent or guardian before Monday!!!!!