Question

(-4)+[15+(-3)]=[-4+15]+...................

Answer 1

the result on the l.h.s is 8, using the brackets. so the result on the r.h.s should also be 8. so the correct number that will fill the blank will be -3.

Answer 2

LHS,

(-4)+[15+(-3)] 

= -4+[15-3]

= -4+12

= 8

on RHS,

let the blank will be filled with x,

then 

=[-4+15]+x

= 11+x

as both are equal 

now,

 8=11+x

8-11 = x

-3 = x


Now the blank will be filled with (-3)

i hope this will help you 

- by ABHAY