Solving Two Step Equations

Warm Up1. 9s + 3 = 57 2. + 9 = 30

3. -9h – 15 = 93 4. 7(c – 12) = -21

5. 4d + 6 = 42 6. – 7 = 15

• Isolating the variable means getting the variable alone on one side of the equation.

• To maintain equality, an operation must be applied to both sides of the equation.

• Equations with negative numbers are solved in the same way as equations with positive numbers.

• When solving a two-step equation, the inverse operations are applied in the opposite order from the order used when simplifying an expression: first, addition or subtraction; then multiplication or division.

The Tip Top Bakery receivesseveral orders, each for 3 dozen

dinner rolls. The baker made200 dinner rolls. After the orders

are filled there are 20 rolls left.How many orders for 3 dozen rolls

does the bakery receive?

4x + 7 = 23

As a reward for winning a mathcompetition, 26 students in the 7thgrade visited a theme park. On one

ride, 3 equal groups of students couldbe seated and 2 students were left

over. Write and solve an equation tofind how many students could be

seated in each group.

To convert from degrees Celsius todegrees Fahrenheit, first multiply

by . Then add 32 to the result. Anindoor thermometer showed a

temperature of -13 °F. What wasthe temperature in degrees

Celsius?

You are saving to buy a mountainbike that costs $280. Each week you save $15. At this rate, how

many weeks will it take to have a balance of $100 left to save?

Solve

-5.5x + 0.56 = -1.64

-4.2x + 31.5 = -65.1

+ 81.9 = 47.2

A student’s solution to the equation 3x + 2 = 15 is shown.

Describe and correct the error that the student made.

Solve the equation ax + b = c for x.

Exit Ticket1. Solve 22 - 3b = 7 for b.

2. Solve 4(x - 5) = 92 for x.

3. Eya is 5 years younger than 3 times Bill's age. If Eya is 28 years old, how old is Bill?

4. What is the temperature in degrees Fahrenheit of a freezer kept at -25 °C?