Hello!
You can only add variables with the same base and exponent
8u^3 + 4u^3 = 12u^3
8u^2 + 0 = 8u^2
0 + -6u = -6u
6 + 3 = 9
Put the sums together
12u^3 + 8u^2 - 6u + 9
The answer is

Hope this helps!
Answer:
10
Step-by-step explanation:
48-20=28
28-18=10
that is how I see it at least
Are you sure about your solves??
I think correct answer is 6,
I don't know but the standard way is in the photo:
Factors of 38
1, 2, 19, 38
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1×38
2×19
Factors of 59
1, 59
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Common factors for 38 and 59
1 is the only common factor
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GCF of 38 and 59
1 is the both the common and GCF of 38 and 59