Solve the following equation

Explanation

We will use a property of equality to isolate the variable on one side of the equation. To solve the original equation, we want to find a simpler equivalent equation of the form, whose solution is obvious.

To isolate x, we use the subtraction property of equality.  We can undo the addition of 54.9 by subtracting 54.9 from both sides.

• This is the equation to solve
  • 54.9 + x = 45.2
• Subtract 54.9 from both sides
  • 54.9 + x - 54.9 = 45.2 - 45.9
• On the left side, 54.9 - 54.9 = 0
  • x = -9.7

Check

• This is the original equation
  • 54.9 + x = 45.2
• Substitute -9.7 for x
  • 54.9 + (-9.7) = 45.2
  • 45.2 = 45.2 (which is true)

The solution is -9.7