Question 873826
It's not an equation because it doesn't have an equal sign.
I'll assume it's
{{{ -16t^2+50t+4=0}}}
Complete the square,
{{{-16(t^2-(50/16)t+(25/16)^2)+4+16((25/16)^2)=0}}}
{{{-16(t-25/16)^2+64/16+625/16=0}}}
{{{-16(t-25/16)^2=-689/16}}}
{{{(t-25/16)^2=689/256}}}
{{{t-25/16=0 +- sqrt(689)/16}}}
{{{t=25/16 +- sqrt(689)/16}}}