First, add #color(red)(3t)# and #color(blue)(10)# to each side of the equation to isolate the #t# term while keeping the equation balanced:
#6 - 3t + color(red)(3t) + color(blue)(10) = t - 10 + color(red)(3t) + color(blue)(10)#
#6 + color(blue)(10) - 3t + color(red)(3t) = t + color(red)(3t) - 10 + color(blue)(10)#
#16 - 0 = 1t + color(red)(3t) - 0#
#16 = (1 + color(red)(3))t#
#16 = 4t#
Now, divide each side of the equation by #color(red)(4)# to solve for #t# while keeping the equation balanced:
#16/color(red)(4) = (4t)/color(red)(4)#
#4 = (color(red)(cancel(color(black)(4)))t)/cancel(color(red)(4))#
#4 = t#
#t = 4#