The distributive rule: "To multiply a sum by a number, multiply each term of the sum"
[tex]m\cdot(a\text{ + b) = m}\cdot a\text{ + m}\cdot b[/tex]We have to:
[tex]6\cdot x\cdot\text{ (1 }+x\text{) = 6}\cdot x+6\cdot x^2\text{ }[/tex]The answer is:
[tex]6\cdot x\text{ }+\text{ 6}\cdot x^2[/tex]