# 2 7 solving proportions Objective 1 Solve problems

2. 7 solving proportions Objective: 1. Solve problems using proportions

A comparison of two numbers, usually written as a fraction. Ratio: Proportion: --An equation stating that two ratios are equal --(or two equal fractions) Where b ≠ 0 and d ≠ 0. What do you notice happens when you multiply the diagonals on the following proportion?

Please solve for x in each of the following. 3 = x 7 = 49 5 20 4 = 10 X 56 7 x 3 (20) = 5(x) 7(56) = 49(x) 7(10) = 4(x) 12 = x 8 = x 17. 5 = x

solve for x 4 (x – 8) = 5(x + 3) 4 x – 32 = 5 x + 15 - 5 x______ -1 x – 32 = 15 + 32 +32 -1 x = 47 -1 x = - 47

Using a proportion to solve a problem. A portable media player has 2 gigabytes of storage and can hold about 500 songs. A similar but larger media player has 80 gigabytes of storage. About how many songs can the larger media player hold? Know Need 2 gigabytes holds 500 songs The number of songs the larger player holds Larger player has 80 gigabytes Plan Write a proportion and solve. 2 x = 500(80) 2 x = 40, 000 2 2 x = 20, 000 The larger media player holds 20, 000 songs

homework Pg 127: 10 -36 evens, 51, 52 • Note: showing work is optional through 24, required past that.

- Slides: 6