PLEASE HELP BRAINLIEST REWARDED TO CORRECT ANSWERMickey simplified the expression below. He then checked his work by substituting 4 for x. He noticed his two values were not equal. What was Mickey’s error when simplifying?Expression: 2x^2 - 4x - 9 - x^2 + 2x + 3Simplified expression: x^2 - 6x - 6ANSWER CHOICES: Mickey should have added –4 and 2 when combining the coefficients of the x terms.Mickey should have added 2 and 1 when combining the x^2 terms.Mickey should have added 9 and 3 when combining the constant terms.Mickey should have added –4 and –1 when combining the x terms.