Question

$draw \: a \: quadrilateral \: and \: show \: that \: the \: sum \: of \: all \: angle \: is \: 360 \: degree$
$the \: sum \: of \: all \: angle \: is \: 360 \: degree$
​

Answer 1

Answer:

factorise completely the following polynomial 3x

3

+2x

2

−19x+6

Medium

Video Explanation

Solution To Question ID 578138

Answer

Let f(x)=3x

2

+2x

2

−19x+6

Using hit and trial method,

f(1)=3+2−19+6



=0

f(−1)=−3+2+19+6



=0

f(2)=24+8−38+6=0

∴(x−2) is a factor of f(x).

3x

2

+8x−3

Now, x−2

)3x

2

+2x

2

−19x+6

3x

2

−6x

----------------------------------

8x

2

−19x

8x

2

−16x

------------------------------------

−3x+6

−3x+6

-------------------------------------

x

--------------------------------------

To factorise 3x

2

+8x−3

=3x

2

+9x−x−3

=3x(x+3)−1(x+3)

=(3x−1)(x+3)

Hence 3x

3

+2x

3

−19x+6=(x−2)(3x−1)(x+3)

Answer verified by Toppr