$12.98;{ m{\% ;of;}}399.98 + sqrt ? = frac{{1.98}}{{2.93}}{ m{;of;}}125.98$

$13 imes 4 + sqrt ? = frac{2}{3} imes 126$

$52 + sqrt ? = 84$

$sqrt ? = 84 - 52$

$sqrt ? = 32 Rightarrow ? = 1024$