Find and explain the error in the work below.
simplify -5x+15-2+9x
The error in the given work is a mistake in combining like terms.
The given expression is: -5x + 15 - 2 + 9x
In order to simplify the expression, we need to combine the like terms, which means grouping the terms with the same variable together.
Starting with the -5x and 9x terms, we can combine them since they both involve the variable x. Combine the coefficients of x, which gives us 9x - 5x = 4x.
So now the expression becomes: 4x + 15 - 2
Next, we can combine the constants 15 and -2. Adding them together gives us 13.
Therefore, the simplified expression is: 4x + 13.
The error in the given work is that the like terms -5x and 9x were not correctly combined, resulting in an incorrect answer.