0,8 and 1,140

which is the biggest? and why?

Give them all the same decimal places and then compare:

0,800

1,140

Now you can compare them on equal footing.  If we cut out the decimal,

Is 1140 or 800 greater?

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong

if you was gonna solve for a, a is a   < -12