Answer:
4x²
Step-by-step explanation:
Your equation is 4x² - 6x² + 7x² - 20x² + 19x².
Since they all have the same variable, simply combine them all to find your answer.
4x² - 6x² + 7x² - 20x² + 19x²
-2x² + 7x² - 20x² + 19x²
5x² - 20x² + 19x²
-15x² + 19x²
4x²