Distributive Laws

It says that multiplying a number by a group of numbers added together is same as doing each multiplication separately. 

1. a * ( b + c ) = a * b + a * c

Examples : 

1. 7 * (50 - 2 )
   = 7 * 48
   = 336
lets rearrange
( 7 * 50 ) - (7*2)        [ here, a * ( b - c ) = a * b - a * c]
=350 -14
= 336 

2. 625 * (-35) + ( -625 ) * 65 
 that is ,  [ 625 * (-35) ] +  [ ( -625 ) * 65 ]
              = (-21,875 ) + ( -40,625 )
              = - 62,500
lets rearrange
[ 625 * (-35) ] +  [ ( -625 ) * 65 ]
here, 625 is common in both , so lets take 625 out
that is, 625 * ( -35 - 65 ) 
          = 625 * -100
          = - 62,500