Question 878902
The key is realizing that {{{(m+3)^3=(m+3)(m+3)^2}}} , and then taking {{{(m+3)^2}}} out as a common factor.
The rest is just understanding symbols and order of operations conventions in the language called "algebra".
{{{5(m+3)^2 - 4(m+3)^3= 5(m+3)^2 - 4(m+3)(m+3)^2}}}{{{"= ["}}}{{{5-4(m+3)}}}{{{"]"}}}{{{ (m+3)^2=
(5-4m-12)(m+3)^2}}}
={{{(-4m-7)(m+3)^2=(-1)(4m+7)(m+3)^2=highlight(-(4m+7)(m+3)^2)}}}