Question

factorise y cube minus 7 Y + 6​

Answer 1

Answer:

Step-by-step explanation:

(y-1) is a factor of y^3-7y+6 because at y=1, our equation becomes: 1^3-7+6=1-7+6=7-7=0.

Thus, we can proceed as follows:

y^3-7y+6

=y^3 - y^2 + y^2 - y - 6y + 6

=y^2(y-1) + y(y-1) -6(y-1)

=(y-1) {y^2 + y - 6}

=(y-1) {y^2 + 3y - 2y - 6}

=(y-1) {y (y + 3) - 2 (y + 3)}

=(y-1) {(y + 3) (y - 2)}

=(y-1) (y+3) (y-2)

These are the factors. There are three factors as it is a cubic polynomial. The zeros are 1, -3 and 2. Hope it helps.