Answer:
To calculate the expression (7x^3 - 8x^2 + 4x + 9) - (3x^2 - 2x + 9), you need to perform subtraction of the terms with the same degree of x. Here's how you do it:
(7x^3 - 8x^2 + 4x + 9) - (3x^2 - 2x + 9)
First, distribute the negative sign to all terms inside the parentheses:
= 7x^3 - 8x^2 + 4x + 9 - 3x^2 + 2x - 9
Now, combine like terms. Group the x^3 terms, x^2 terms, x terms, and constants:
(7x^3) - (3x^2) + (-8x^2 + 2x) + (4x) + (-9 + 9)
Now, simplify each group:
= 7x^3 - 3x^2 - 8x^2 + 2x + 4x - 0
Combine like terms again:
= 7x^3 - (3x^2 + 8x^2) + (2x + 4x) - 0
= 7x^3 - 11x^2 + 6x
So, the simplified expression is:
7x^3 - 11x^2 + 6x
Explanation: