Question

(iv) y + y - y - 1
${y}^{3} + {y}^{2} - y - 1$
factorize​

Answer 1

= y³+y²-y-1

= y²(y+1)-1(y+1)

= (y²-1)(y+1)

= (y²-1²)(y+1)

by a²-b²= (a+b)(a-b)

so y²-1² = (y-1)(y+1)

= (y-1)(y+1)(y+1)

= (y-1)(y+1)²