Question

уравнение 1 300- ( d - 678 ) = 400

Answer 1

1 300- ( d - 678 ) = 400

- ( d - 678 ) = 400-1300

- ( d - 678 ) = -900

( d - 678 ) =900

d =900+678

d =1578

Answer 2

1 300- ( d - 678 ) = 400

d-678=1300-400

d-678=900

d=900+678

d=1578