#16t^2 - 12t - h = 0#
you would need to complete the square:
#ax^2+bx +c#
#a=1#
#c=(1/2b)^2#
So first move the #h# over:
#16t^2 - 12t = h#
now divide by 16 so #a=1#
#(16t^2 - 12t)/16 = h/16#
#t^2 - 3/4t = h/16#
now we are ready to complete the square:
#t^2 - 3/4t +c = h/16 +c#
#c=(1/2b)^2#
#c=(1/2*-3/4)^2 = 9/64#
#t^2 - 3/4t +9/64 = h/16 +9/64#
#(t-3/8)^2 = h/16 +9/64#
#sqrt((t-3/8)^2)=+-sqrt( h/16 +9/64)#
#t-3/8=+-sqrt( h/16 +9/64)#
#t=3/8+-sqrt( h/16 +9/64)#
#t=3/8+-sqrt( (4h)/64 +9/64)#
#t=3/8+-sqrt( (4h+9)/64)#
#t=3/8+-sqrt( (4h+9))/8#
#t=(3+-sqrt( 4h+9))/8#