(x4 − 9x + 5x7) + (5x − 10 + 3x4 − 2x2)

= 5x^7 + 4x^4 - 2x^2 - 4x - 10

To simplify the given expression, we need to combine like terms. Let's break it down step-by-step:

First, let's group the like terms:
(x^4 - 9x + 5x^7) + (5x - 10 + 3x^4 - 2x^2)

Next, let's combine the x^4 terms:
(x^4 + 3x^4 - 9x + 5x^7) + (5x - 10 - 2x^2)

Now, let's combine the x terms:
(x^4 + 3x^4 - 9x + 5x - 10 + 5x^7 - 2x^2)

Let's combine the like terms:
(4x^4 - 4x - 10 + 5x^7 - 2x^2)

The simplified expression is:
5x^7 + 4x^4 - 2x^2 - 4x - 10

To simplify the given expression, we need to combine like terms, which means adding or subtracting variables with the same exponent or degree.

Let's break down the expression term by term:

(x^4 − 9x + 5x^7) + (5x − 10 + 3x^4 − 2x^2)

Step 1: Combine like terms with the same exponent of x:
5x^7 + x^4 + (-9x + 5x) + (-2x^2 - 10)

Step 2: Simplify each group of like terms:
5x^7 + x^4 - 4x - 2x^2 - 10

Therefore, the simplified form of the expression is:
5x^7 + x^4 - 2x^2 - 4x - 10