It is given that, the expression 9x7 represents strawberries each person received when splitting x containers.
Now 9x7=9*7*x=63 x----Natural number satisfies Associative property with respect to Multiplication
There were 7 friends who split x containers of Strawberries.
So,total number of Containers=x+x+x+x+x+x+x=7x
So, number of Strawberries received by each person
[tex]\rightarrow\frac{63}{7}\\\\=9[/tex]