Lesson 12: Solving Problems About Percent Increase or Decrease | Unit 6: Expressions, Equations, and Inequalities

Here are two stories: * The initial freshman class at a college is 10% smaller than last year’s class. But then during the first week of classes, 20 more students enroll in the class. There are then 830 students in the freshman class. * A store reduces the price of a computer by $$20. Then during a 10$$ 830 for the computer. Here are two equations: * $$0.9x+20=830$$ * $$0.9(x-20)=830$$ Explain why one equation has parentheses and the other doesn’t.

Here are two stories: * The initial freshman class at a college is 10% smaller than last year’s class. But then during the first week of classes, 20 more students enroll in the class. There are then 830 students in the freshman class. * A store reduces the price of a computer by $$20. Then during a 10$$ 830 for the computer. Here are two equations: * $$0.9x+20=830$$ * $$0.9(x-20)=830$$ Solve each equation, and explain what the solution means in the situation.

Jada, Elena, and Lin walked a total of 37 miles last week. Jada walked 4 more miles than Elena, and Lin walked 2 more miles than Jada. The diagram represents this situation: Find the number of miles that they each walked. Explain or show your reasoning.