## Prealgebra (7th Edition)

$2a(5a+6)$
First find the greatest common factor of $10a^2\ and\ 12a$. Find the prime factors of each. $10a^2=\underline2 \times 5 \times \underline a\times a$ $12a= \underline2 \times2\times3 \times \underline a$ The greatest common factor is the product of the common factors (underlined above). $2\times a=2a$ $10a^2+12a=2a(5a+6)$