Question

factorise 2y³+y²-2y-1
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Answer 1

Answer:

Given that 2y³ + y² – 2y – 1

Now Factorizing

2y³ + y² – 2y – 1

= y² (2y + 1) -1 (2y + 1)

= (2y + 1)(y² – 1)

= (2y + 1)(y² – 1²)

By algebraic identity:

a² – b² = (a + b) (a – b)

(y² – 1²) = (y + 1)(y – 1)

(y² – 1²) can be written as (y + 1) (y – 1)

∴ (2y + 1)(y² – 1²)= (2y + 1) (y + 1) (y – 1)

Therefore,

2y³ + y² – 2y – 1 = (2y + 1) (y + 1) (y-1)

Answer 2

Answer:

2y³+y²-2y-1

=2y³-2y+y²-1

=2y(y²-1)+1(y²-1)

=(2y+1)(y²-1)

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