ok wat u do first is let me show u
103*[12/(10-4*2)]+3
103*12/[(10-8)]+3 cause u multiply 4*2 first
103*12/[2]+3 then u subtract 10-8 next
then u multiply 103*12 which =1236 then
divid 1236/2 by 2 which =618
next u add 618 by 3 then it =621 and theres yur answer