factor the following expression? Do not leave negative exponents.

21(x−8)^1/4 (x^2+7)^2/3 +14(x−8)^5/4(x^2+7)^−1/3

You can see there is (x-8) and (x^2+27) in both terms.

You probably want to factor out the lowest power of those factors.
also, 21 and 14 are both multiples of 7, so
21(x−8)^1/4 (x^2+7)^2/3 +14(x−8)^5/4(x^2+7)^−1/3
7(x-8)^1/4 (x^2+7)^-1/3 (3(x^2+7) + 2(x-8))
7(x-8)^1/4 / (x^2+7)^1/3 (3x^2+21+2x-16)

7(x-8)^1/4 (3x^2+2x-5)
-------------------------------
(x^2+7)^1/3

or

7(x-8)^1/4 (x-1)(3x+5)
-------------------------------
(x^2+7)^1/3

oops. 21-16 = 5, not -5

7(x-8)^1/4 (3x^2+2x+5)
-------------------------------
(x^2+7)^1/3

To factor the given expression, we can first factor out the common terms from both terms of the expression.

The common factors are (x−8)^1/4 and (x^2+7)^1/3.

Factoring out the common factors, we have:

21(x−8)^1/4 (x^2+7)^2/3 + 14(x−8)^5/4(x^2+7)^−1/3

= (x−8)^1/4 (x^2+7)^1/3 [21(x^2+7) + 14(x^−8)^5/4]

Now, let's simplify the expression within the brackets:

= (x−8)^1/4 (x^2+7)^1/3 [21x^2+147 + 14(x−8)^5/4]

To simplify further, we can expand (x−8)^5/4 as (x−8)(x−8)(x−8)(x−8)(x−8)^1/4 and simplify (x^−8)^1/4 as √(x−8), and distribute the factors:

= (x−8)^1/4 (x^2+7)^1/3 [21x^2+147 + 14(x−8)(x−8)(x−8)(x−8)√(x−8)]

= (x−8)^1/4 (x^2+7)^1/3 [21x^2+147 +14(x^5−40x^4+480x^3−2560x^2+4096)√(x−8)]

Now, we have factored the given expression by factoring out the common factors.