### Instruction: Simplify $(2x^2 + 7x - 3) - (x^2 + 5x - 12)$.### Response: This problem asks me to subtract one quadratic polynomial from another.
I can use the distributive property of subtraction to rewrite this as $2x^2 + 7x - 3 - x^2 - 5x + 12$.
Now I can combine like terms by adding or subtracting the coefficients of each power of x.
I have $2x^2 - x^2 = x^2$, $7x - 5x = 2x$, and $-3 + 12 = 9$.
So the simplified expression is $x^2 + 2x + 9$.