Answer:
5x^4
Step-by-step explanation:
When you need to find the GCF where there is multiple terms and variables, start by looking at them one at a time and break the terms apart.
GCF of 5, 30, and 10: 5
Factors of 5: 1*5
Factors of 30: 1*30, 2*15, 3*10, 5*6
Factors of 10: 1*10, 2*5
The greatest factor that those numbers all have in common is 5.
GCF of the variables: x^4
(5)x^7: x*x*x*x*x*x*x
(30)x^4: x*x*x*x
(10)x^4: x*x*x*x
The greatest number of x's that those variables have in common is 4.
Therefore, the answer is 5x^4.
