Ce numere se descompun astfel

____9x100+2x10+7x1

____=8x10+6x10+4x1

____9x100+8x10+5x1

____=2x100+2x10+2x1

Coloana(b)

____=5x100±7x10+7x1

____7x100+9x10+4x1

____6x100+6x10+3x1
.
____=3x100+9x10+7x1

Urgent