Question

21. Factorise : x2 - 3x - 28​

Answer 1

Answer:

x2+3x−28x2+3x-28

Consider the form x2+bx+cx2+bx+c. Find a pair of integers whose product is cc and whose sum is bb. In this case, whose product is −28-28 and whose sum is 33.

−4,7-4,7

Write the factored form using these integers.

(x−4)(x+7)(x-4)(x+7)

Answer 2

Answer:

x^2 - 3x - 28

x^2 - 7x + 4x - 28

x (x - 7 ) + 4 ( x - 7 )

(x + 4 ) ( x - 7 )