Question

1. Find the roots of the following quadratic equations, if they exist, by the method of factorisation

(i) 2x2 – 7x +3 = 0
(ii) 2x2 + x – 4 = 0
(iii) 4x2 + 4√3x + 3 = 0
(iv) 2x2 + x + 4 = 0​

Answer 1

Answer:

a). 2x2−7x+3=0

⇒x2−27x=−23

Adding (47)2 on both sides

⇒x2−27x+(47)2=2−3+(47)2

⇒(x−47)2=2−3+1649

⇒(x−47)2=1625

⇒(x−47)2=(45

Taking square root on both sides

⇒(x−

4

7

)=±

4

5

⇒x−

4

7

=

4

5

, x−

4

7

=

4

−5

x=

4

5

+

4

7

x=

4

−5

+

4

7

x=3 x=

2

1

b). 2x

2

+x−4=0

x

2

+

2

x

=2