how do you guys type equations so neatly and all of your things look the same what program are you all using

$\displaystyle x = 0.5gt^2 $

$\displaystyle ln(x) = ln(0.5gt^2) $

$\displaystyle ln(x) = ln(0.5g) + ln(t^2) $

$\displaystyle ln(x) = 2ln(t) +ln(0.5g) $

$\displaystyle a = v^2/r $

they never work for me ):

OMGG it workedd!!

is there any program where i can type it out like this on my computer?