[tex] {7x}^{3} . \: {7x}^{5} . {7x}^{2} \\ 343 {x}^{3} {x}^{5} {x}^{2} \\ 343 {x}^{10} \\ [/tex]
[tex]7x^3\cdot 7x^5\cdot 7x^2 =(7)^3\cdot x^{2+3+5} =343x^{ {10}}[/tex]
