4/9___=12 let the space no. to b found=x then Question becomes............4/9dividedx=12.....next step....equation becomes 4/9into 1/x=12 ..............i.e 4/9x=12.........next ...........4/x=12into9...........i.e 4/x=108..........or 1/x=108divided by 4..............1/x=27..............and x=1/27 i.e 0.037..............inshort if we divide 4/9 by 1/27 then answer is =12

this question can be solved by  using  math rule DMAS i.e division,multiply.....and so on will b solved accordingly.And bracketsare solved ,first the parenthesis,then mid then square.......answer is -50. i.e first add 7+3 in brac. then multiply the sum with -5 .so -5x10=-50..............ask more for any Question if u need explanation.

answer is :diameter/2=radius so 6/2=3 and circumference=2into pi into3=2into3.14into3=18.84