Answer:
[tex] \huge { \red{\boxed{ \boxed{ \tt \: 3(1 + 6d + 7y)}}}}[/tex]
Step-by-step explanation:
to understand this
you need to know about:
let's solve:
in the following expression
everytime 3 is common
(3×1)+(3×6d)+(3×7d)
therefore if you take 3 from every expression we get
which is a product of two factors
