Question

factorise

y²+6y-27

plz plz plz​

Answer 1

Answer :-

(y - 9)(y + 3)

Solution :-

y² + 6y - 27

Splitting the middle term

First multiply last term and first term

- 27 * y² = - 27y²

Now we need to find factors which sums to middle term i.e, - 6y

- y * 27y

- 9y * 3y

So, we got - 9y and 3y which sums to middle term i.e, - 6y( - 9y + 3y = - 6y)

So replace - 6y with - 9y + 3y in the expression

= y² - 9y + 3y - 27

= y(y - 9) + 3(y - 9)

= (y - 9)(y + 3)

Answer 2

Solution

By using middle term splitting

First multiply the first term and the last term i.e y² * - 27

=> - 27y²

Now factorise it and arrange the factor in such a way that by adding it come 6y

=> - 9 + 3

Instead of using 6y we will use - 9y + 3y

=> y² - 9y + 6y - 27

=> y *y - 9 *y + 3*y - 3 *9

Take the common factor

=> y(y - 9) + 3(y - 9)

$\large \bold{ \underline{ \boxed {=> (y- 9) ( y + 3) }}} \: \: \: \:$