1. Do Now
Identify whether the equation has exactly one solution, no solution, or infinitely many solutions. 4y – 7 + 2y = -3(y – 1) – 1 x + 2(x – 7) = 3x - 7

2. Literal Equations and Formulas
Lesson 1-4

3. Developing a Formula for Perimeter

4. Determining the length if you know the width and perimeter

5. Formulas and Literal Equations
A formula is an equation that states a relationship between one quantity and one or more quantities.
EX: The perimeter of a rectangle is P = 2l + 2w, where l is the length and w is the width of the rectangle.
A literal equation is an equation that is expressed in letters only.
EX: d = rt

6. Moving Parts of a Literal Equation

7. Example using d = rt
d is the distance an object has traveled r is the rate at which the object travels t is the time the object is traveling

8. Example using d = rt
In a half hour, Sarah is meeting her friends at the lake, 6 miles from her house. At what average speed must she ride her bike to get there on time? STEP 1: Solve the distance formula for r. STEP 2: Find the average speed, or rate, at which Sarah must ride her bike to be on time.

9. Examples
Solve each equation for the indicated variable. k = a – y ; y w = 𝑥 𝑎 −𝑏 ; x y(a – b) = c(y + a) ; y

10. With a Partner
Solve each equation for the indicated variable. u = x(k + l); x a – c = d – r ; a y = 3 5𝑢 +5 ; u

11. On your Own
Solve for the indicated variable. 4x – 3y = 12; y z = 𝑎−𝑏 𝑡 ; a V = 1 3 𝜋 𝑟 2 (ℎ −1) ; h

12. Word Problem #1
According to Teo’s bread recipe, he should bake the bread at 190°C for 30 minutes. His oven measures temperature in °F. To what temperature in °F should he set his oven? C = 5 9 (𝐹 −32)

13. Exit Slip
Solve the equations for the indicated variable. ax + by = c ; y A = 𝑥+𝑦 2 ; x P = IRT ; R

14. Do Now
Solve the equations for the indicated variable. 9y – 3x = 6; y 𝑤+𝑟 𝑧 =𝑓 ; w f = ma; a

15. Examples
Solve the literal equation for the indicated variable. V = 𝜋 𝑟 2 ℎ ; h y = mx + b ; m A = 2(L + W)

16. Group Solving
Each group will get a literal equation to solve for a variable.
Use a mobile device to discover the name of the literal equation.
Solve the literal equation for the indicated variable.

17. Presentations!
If your group volunteers to present their solution, then both students will get 5 extra credit points.

18. Word Problem #2
The area of a triangle is given by the formula 𝐴= 𝑏ℎ . If a triangle has a base of 7 m and an area of 17.5 m², what is its height?

19. Independent Practice p. 28 11, 13-23 odd only, 31 (part a and b)

20. Homework Questions?