Answer:
Step-by-step explanation:
She added 3x and -2x, getting 5x, instead of x. She needs to pay more attention to the positive/negative signs.
Answer:
x-axis
Step-by-step explanation:
In order to simplify a fraction, we have to find a common factor in both numerator and denominator. So, let's start by factor the expressions completely: at the numerator we have

At the denominator we have

So, the fraction can be written as

You can see that there is a factor
in common, that can be simplified:
