1. Warm-Up Exercises Subtract b from each side. Write original equation. Solve ax + b = c for x. STEP 1 SOLUTION Solve ax + b = c for x. Then use the solution to solve 2x + 5 = 11. Solve a literal equation EXAMPLE 1 x c – b a = ax + b = c ax = c – b Assume a  0. Divide each side by a.

2. Warm-Up Exercises GUIDED PRACTICE for Example 1 1. a – bx = c ; 12 – 5x = –3 Solve the literal equation for x. Then use the solution to solve the specific equation

3. Warm-Up Exercises GUIDED PRACTICE for Example 1 2. ax = bx + c ; 11x = 6x + 20 Solve the literal equation for x. Then use the solution to solve the specific equation

4. Warm-Up Exercises Divide each side by 2. Write original equation. Write 3x + 2y = 8 so that y is a function of x. EXAMPLE 2 Rewrite an equation Subtract 3x from each side. 3x + 2y = 8 2y2y = 8 – 3x 3 2 y=4 – x

5. Warm-Up Exercises GUIDED PRACTICE 3. Write 5x + 4y = 20 so that y is a function of x.

6. Warm-Up Exercises

7. GUIDED PRACTICE for Examples 2 and 3 The perimeter P of a rectangle is given by the formula P = 2l + 2w where l is the length and w is the width. a. Solve the formula for the width w. 4.

8. Warm-Up Exercises Use the rewritten formula to find the height of the triangle shown, which has an area of 64.4 square meters. b. Solve the formula for the height h. a. EXAMPLE 3 Solve and use a geometric formula The area A of a triangle is given by the formula A = bh where b is the base and h is the height. 1 2

9. Warm-Up Exercises EXAMPLE 4 Solve a multi-step problem You are visiting Toronto, Canada, over the weekend. A website gives the forecast shown. Find the low temperatures for Saturday and Sunday in degrees Fahrenheit. Use the formula C = (F – 32) where C is the temperature in degrees Celsius and F is the temperature in degrees Fahrenheit. 5 9 Temperature

10. Warm-Up Exercises Simplify. Write original formula. EXAMPLE 4 Solve a multi-step problem Multiply each side by, the reciprocal of. 9 5 5 9 Add 32 to each side. SOLUTION STEP 1 Rewrite the formula. In the problem, degrees Celsius are given and degrees Fahrenheit need to be calculated. The calculations will be easier if the formula is written so that F is a function of C. (F – 32) 5 9 C= F – 32C 9 5 = 9 5 C + 32 = F · (F – 32) 9 5 5 9 C 9 5 =

11. Warm-Up Exercises 1. Write the equation 15 = 5y – 4x so that y is a function of x. 2. Solve C = 2  r for r. 3. Solve V = Bh for B. 1 3