Answer:
11x² - 3x
Step-by-step explanation:
Here's one way to do it. Write the two polynomials with corresponding powers of x under each other and subtract.
12x² - 5x
-(x² - 2x)
Distribute the -1 and add.
12x² - 5x
-x² + 2x
11x² - 3x
Check:
x² - 2x
+(11x² - 3x)
12x² - 5x
OK.