Answer:
2c
Explanation:
c is a common factor of both terms
Consider the factors of the coefficients 4 and 18
factors of 4 : 1, 2, 4
factors of 18 : 1, 2, 3, 6, 9, 18
The common factors are 1, 2
The greatest common factor is 2
Combining with c gives
Greatest common factor of 2c