Question

factories 15(a-2b)²- 8(a-2b)-16​

Answer 1

Answer:

Given: △ABC is a right angled triangle.

Hypotenuse AC=5cm

and AB:BC=1:2

⇒ AB=1x,BC=2x

In right angled △ABC,

By pythagoras theorem

AC

2

=AB

2

+BC

2

⇒5

2

=(1x)

2

+(2x)

2

⇒25=x

2

+4x

2

⇒25=5x

2

⇒x=

5

Hence, AB=1x=1×

5

=

5

cm

BC=2x=2×

5

=2

5

cm

Answer 2

Question -

Factorise - 15(a-2b)² - 8(a-2b) - 16

Solution -

Let, a-2b = x

So,

=15x²- 8x-16

By splitting the middle term,

= 15x² -(20-12)x - 16

= 15x² - 20x + 12x-16

= 5x(3x- 4) + 4(3x-4)

Taking (3x-4) common,

= (3x-4)(5x+4)

We have taken x= 2a-b

Therefore,

=[3(a-2b-4)] [5(a-2b+4)]

=(3a-6b-12)(5a-18b+20)

Required answer is (3a-6b-12)(5a-18b+20)