Cho hai đa thức
P(y)=6y3+5y-3y2-1
Q(y)=5y2-4y3-2y+7
a/tính P(y)+Q(y)
b/ tính P(y)-Q(y)
a/
+ P(y)= 6y3+5y-3y2-1 => P(y)=6y3-3y2 + 5y -1
+ Q(y)=5y2-4y3-2y+7 => Q(y)= -4x3 + 5y2 - 2y + 7
P(y)= 6y3 -3y2 + 5y -1
+Q(y)= -4x3 + 5y2 - 2y + 7
____________________________
P(y)+Q(y) = 2x3 + 2y2 + 3y + 6
b)
P(y)= 6y3 -3y2 + 5y -1
-Q(y)= -4x3 + 5y2 - 2y + 7
____________________________
P(y)-Q(y) = 10x3 - 8y2 + 7y - 8