Solving Two-Step Equations
5x - 10 = 20
6
6x + 11 = 65
x = 9
There are 47 trees currently in the park. Park workers will plant more trees today. When they're done, there will be 57 trees in the park. How many trees did the workers plant?
47 + x = 57
x = 10 trees
What is a variable?
a symbol (usually a letter) standing in for an unknown numerical value in an equation
3.5x = 130 + 10x
-20
3(x + 1) = 21
6
After paying $7 for a stack of brownies, Lacey has $71 left. How much money did she have before buying the brownies?
x - 7 = 71
x = $78
What operation is the inverse of division?
Multiplication
15 - 4x = 10x + 45
-30/14 = -15/7 = -2.14
x/2 - 5 = 25
x = 15
424 students went on a trip to the zoo. All 7 buses were filled, and 4 students have to travel in cars. How many students were in each bus?
7x + 4 = 424
x = 60 Students
What operation is the opposite of subtraction?
Addition
2 + 3(x+1) = 6x
5/3 = 1.67
g/-5 + 3 = -13
g = 80
After eating at a restaurant, Fred, Sam, and Janice decided to divide the bill evenly. If each person paid $42, what was the total of the bill?
x/3 = 42
x = $126
Complete the process of solving the equation.
Fill in the missing term on each line. Simplify any fractions.
2d+4=12
2d=
2d=8
d=4
-2(2x - 3) = -2
2
2/3x + 4 = 16
x = 18
A roller-skating rink charges a $16 fixed fee plus $7 an hour for a party. Laurie paid $79 to rent the rink. How many hours did she pay to have her party?
16 + 7x = 79
x = 9 hours
Find the error in the following work:
2 + 3(x + 1) = 6x
5(x + 1) = 6x
5x + 5 = 6x
5 = x
You must distribute the x3 into the parenthesis before doing addition (PEMDAS).