Question

if a+b = 240
     c+d  = 500
      d-b+c =455
      a+c   =215
find the value for d

Answer 1

Hi,

Four equations are given ,

a + b = 240 -------------------( 1 )

c + d = 500 -------------------( 2 )

c + d - b = 455 ---------------( 3 )

a + c = 215 ---------------------( 4 )

Add equations ( 1 ) and ( 3 ) we get

a + b + c + d - b = 240 + 455

a + c + d = 695 ------------------( 5 )

Subtract eqution ( 4 ) from ( 5 ) we get

a + c + d - ( a + c ) = 695 - 215

a + c + d - a - c = 480

d = 480

I hope this will useful to you.

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