Answer:
14c^2
Explanation:
The greatest common factor is the factor between the 3 expressions that once divided by each expression, 1 becomes the only number common to all 3. Considering all the expressions as follows (broken into all the factors that make up each expression)
14c^3 = 2 × 7 × c × c
70c^4 = 2 × 5 × 7 × c × c × c × c
28c^2 = 2 × 7 × c × c
From the above, the common factors are 2, 7, c and c,the product of these
= 2 × 7 × c × c
= 14c^2