Lesson 2-5Literal Equations and Formulas

September 4, 2014

Daily Learning Target

• I will rewrite and use literal equations and formulas.

Key Vocab.

• Literal equation: an equation that involves two or more variables.

Solve It

• You are ordering pizzas and sandwiches. You have a budget of $80. How many sandwiches can you buy if you buy 4 pizzas?

What if you buy 5 pizzas?

What if you buy 8 sandwiches?

Example 1

10x + 5y = 80

Solve for y

Answer: y = 16 – 2x

Example 2

Solve for x: ax – bx = c

Answer: x =

Example 3

• What is the radius of a circle with a circumference of 64 ft? Round to the nearest tenth. Use 3.14 for p.

Use the appropriate formula: C = 2pr

Answer: r ≈ 10.2 ft.

Example 4

• The monarch butterfly is the only butterfly that migrates annually north and south. The distance a particular group of monarch butterflies is 1700 from Indiana to Mexico. It takes a typical butterfly about 120 days to travel one way. What is the average rate at which a butterfly travels in miles per day? Round to the nearest mile per day.

Answer: r ≈ 14 miles per day

Try It

• This is what you will see on your homework1) 3x – 5y = p; x = -1, 0, 1

2) mx + nx = p; Solve for x.

Homework

• Workbook page 55• Problems: 1, 3, 8, 10, 12, 16, 18

• Page 57• Problems: 1 – 6 ALL