Question 401633
multiply and simplify: (10n + 15) multiply by (n + 1)/ 6n +9

{{{ (10n + 15) * (n + 1)/ (6n +9)}}}
...

{{{(5(cross(2n+3))*(n+1))/(3(cross(2n+3)))}}}
...
{{{5(n+1)/3}}}