\(1560:\left[5.79-\left(125+5.49\right)+5.21\right]=1560:\left[395-370+105\right]\)
\(=1560:130\)
\(=12\)
1560 : [5 x 79-( 125 + 5 x 49 ) + 5 x 21]
=1560 : [5 x 79 -(125+ 245 ) + 5 x 21]
=1560 : [5 x 79 - 370 + 5 x 21]
=1560 : [ 395 - 370 + 105 ]
=1560 : [ 25 + 105 ]
=1560 : 130
=12