Please help me with this is really important here is the picture

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Find the value of x that will make l ll m