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C1:47(45-15)-47(45-25)
=47x30-47x20
=47x(30-20)
=47x10
=470
C2:47(45-15)-47(45-25)
=47x30-47x20
=1410-940
=470
=47.45-47.15-47.45+47.25
=-47.15+47.25
=47(25-15)
=47.10
=470
47( 45 - 15 ) - 47( 45 - 25 )
= 47 . 30 - 47 . 20
= 47 . ( 30 - 20 )
= 47 . 10
= 470
47x(45-15)-47x(45-25)
=47x30-47x20
=(30-20)x47
=10x47
=470