Solve the following equation

Explanation

There are variable terms (3x and 4x) on both sides on the equation.  We will eliminate 3x from the left side of the equation by subtracting 3x from both sides.  To solve for x, all the terms containing x must be on the same side of the equation.

Solution

• This is the equation to solve.  There are variable terms on both sides of the equation
  • 3x - 15 = 4x + 36
• Subtract 3x from both sides to isolate the variable term on the right side
  • 3x - 15 - 3x = 4x + 36 - 3x
• Combine like terms: 3x - 3x = 0 and 4x - 3x = x.  Now we want to isolate the variable x
  
  • -15 = x + 36
• To undo the addition of 36, subtract 36 from both sides.  This isolates x
  • -15 - 36 = x + 36 - 36
• Do the subtraction
  • -15 = x

Check the solution by substituting in the original equation