Question

factorise the following 4x²-16x+15​

Answer 1

Explanation:

To factorize

a

x

2

+

b

x

+

c

, one should split middle term in two parts, so that their product is

a

c

and sum is

b

.

Hence in

4

x

2

−

16

x

+

15

, while the product should be

4

×

15

=

60

, sum should be

−

16

. It is apparent that these are

−

6

and

−

10

.

Hence

4

x

2

−

16

x

+

15

=

4

x

2

−

10

x

−

6

x

+

15

=

2

x

(

2

x

−

5

)

−

3

(

2

x

−

5

)

=

(

2

x

−

3

)

(

2

x

−

5

)