Prealgebra Equations

Which equation has x = 5 as the solution?

• x + 15 = 10

• 2x = 5

• 2x = 10

• Is 'x' a letter of the alphabet?

How should you show your work to separate the variable and solve the equation?

• Add 62 to each side. 

• Subtract 62 from each side.

• Multiply each side by 62.

• Add 123 to each side.

To undo an operation, you must do its opposite or inverse to both sides of the equation. Match each operation to its inverse.

• Addition

• Addition

• Division

• Division

• Multiplication

• Multiplication

• Subtraction

• Subtraction

144 = -12(x+ 5)

• -7

• -17

• 14

• x = 35
  

• x = 0
  

• x = 21
  

• x = 14
  

What is the first step to solve this equation:
11 - 3x = 44

• Add 3 to both sides

• Subtract 11 from both sides

• Add 11 to both sides

• Divide 3 on both sides.

The area of a rectangular deck is 125 square feet. The width of the deck is 25 feet. Write an equation and solve to find the length.

• 25x=125,
  x = 5 feet

• x+22=125,
  x = 20 feet

• x-25=125
  x=150 feet

• 25x=125
  x=3,125 feet

3(2x+5)=39

• x = 4

• x = 5

• x = 3

• x = -2

5(2x-10)=30

• x=8

• x=3

• x=4

• x=10

Solve: -7(x - 6) = -70

• x = 16

• x = -16

• x = 8

• x = -1/2