Chapter 2 Sections 5-6Chapter 2 Sections 5-6

Problem Solving and Problem Solving and FormulasFormulas

Problem SolvingProblem Solving

The length of a rectangle is 6 inches more The length of a rectangle is 6 inches more than its width. The perimeter of the than its width. The perimeter of the rectangle is 24 in. What is the length?rectangle is 24 in. What is the length?

w

w + 6

P = 2l +2w

24 = 2(w+6) + 2(w)

24 = 2w + 12 + 2w

24 = 4w + 12

12 = 4w

3 = w

l = w + 6

l = 3 +6

l = 9 in

The width of a rectangle is 2 cm less than The width of a rectangle is 2 cm less than its length. The perimeter of the rectangle is its length. The perimeter of the rectangle is 16 cm. What is the length?16 cm. What is the length?

l – 2

l

P = 2l + 2w

16 = 2l + 2 (l - 2)

16 = 2l + 2l – 4

16 = 4l – 4

20 = 4l

l = 5 cm

Consecutive Integers-differ by 1.Consecutive Integers-differ by 1.

The sum of three consecutive integers is The sum of three consecutive integers is 147. Find the integers.147. Find the integers.

N: first number

N+1: second number

N +2 : third number

N + N + 1 + N + 2 = 147

3N + 3 = 147

3N = 144

N = 48

48, 49, 50

The sum of three consecutive integers is The sum of three consecutive integers is 48.48.

The sum of four consecutive even integers The sum of four consecutive even integers is 60.is 60.

The sum of two consecutive odd integers The sum of two consecutive odd integers is 44.is 44.

Literal Equation- two or more Literal Equation- two or more variablesvariables

Solve the formula A = ½ bh for Solve the formula A = ½ bh for height h.height h.

Solve the formula for the Solve the formula for the perimeter of a rectangle for the perimeter of a rectangle for the width. P = 2(l + w)width. P = 2(l + w)

Solve the formula V = lwh for w.Solve the formula V = lwh for w.

Transforming EquationsTransforming Equations

Solve y = 5x + 7 for x.Solve y = 5x + 7 for x.

Solve z – br = p for b.Solve z – br = p for b.

Solve y + 2x = 5 for y.Solve y + 2x = 5 for y.

Solve 5x + 4y = 4 for y.Solve 5x + 4y = 4 for y.

Solve 2x + 7y = 4 for y.Solve 2x + 7y = 4 for y.

HW # 6HW # 6

Page 107 (1, 2, 4, 6 -8)Page 107 (1, 2, 4, 6 -8)

Page 113 (1-6, 9 -14)Page 113 (1-6, 9 -14)