Question 129483
Remember the area of any triangle is {{{A=(b*h)/2}}}



{{{A=(b*h)/2}}} Start with the given formula



{{{x^2 + 5x +6=(b*(x + 3))/2}}} Plug in {{{A=x^2 + 5x +6}}} and {{{h=x + 3}}}



{{{2(x^2 + 5x +6)=b*(x + 3)}}} Multiply both sides by 2



{{{2(x + 3)(x+2)=b*(x + 3)}}} Factor {{{x^2 + 5x +6}}} to get {{{(x + 3)(x+2)}}}



{{{(2(x + 3)(x+2))/(x + 3)=b}}} Divide both sides by {{{x + 3}}} to isolate b



{{{(2cross((x + 3))(x+2))/cross((x + 3))=b}}} Cancel like terms



{{{2(x+2)=b}}} Simplify



{{{2x+4=b}}} Distribute



So our answer is 


{{{b=2x+4}}}