Find and explain the error in the work below.

Question

simplify -5x+15-2+9x

Answer 1

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.