Question 195459
I'm assuming that expression equates to zero. 
:
5t(t+5)+(t-1)(t+6)= 0 
:
5(t^2) + 25t + (t-1)(t+6)= 0
:
:Expand the back part of the equation
:
5(t^2) + 25t + (t^2) + 5t - 6 = 0
:
6(t^2) + 30t - 6 = 0
:
(t^2) + 5t - 1 = 0
:
Using formula:
:
{{{t = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
:
{{{t = (-5 +- sqrt( 5^2-4*1*(-1)))/(2*a) }}}
:
t= 0.193(approx. 3 significant figures) or t= -5.19(aprrox. 3 significant figures)