1- Leave the 1st case empty
2- Write on the 1st row each element of the trinomial in each case
3-Write on the 1st column in each case each of the element of the binomial
║ y² -3y 9
----------- ║-----------------------------------------------------
y ║ y³ -3y² 9y
----------- ║---------------------------------------------------
3 ║ 3y² -9y 27
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TOTAL║(y³+3y²) +(-3y²-9y) + ( 9y+27)
If you add the Total you will get: (A) Y³+27
