Question

Consider the following expression: (x − 4) + (2x − 8). Explain what impact changing the addition sign separating the two binomials to a subtraction sign would have on the simplification. Show both simplifications to justify your response.

Answer 1

I'm not sure if this is what you are looking for, but ....

Changing the sign to a subtraction sign would mean that you would have to multiply both terms in the second binomial by -1 before combining like terms with the first binomial. Multiplying by -1 would change the signs on both terms in the second binomial.

x-4+2x-8 simplifies to 3x-12
and
x-4-2x+8 simplifies to 4-x