Question

(x+5)(x-3)=9 quadratic equations

Answer 1

Answer:

5+x

−

5+x

5−x

=3

4

3

⇒

(5−x)(5+x)

(5+x)

2

−(5−x)

2

=

4

15

⇒

(5)

2

−(x)

2

(5)

2

+10x+x

2

−((5)

2

−10x+x

2

)

=

4

15

⇒

25−x

2

25+10x+x

2

−25+10x−x

2

=

4

15

⇒

25−x

2

20x

=

4

15

⇒

25−x

2

4x

=

4

3

⇒ 16x=75−3x

2

⇒ 3x

2

+16x−75=0

⇒ 3x

2

+25x−9x−75=0

⇒ x(3x+25)−3(3x−25)=0

⇒ (3x+25)(x−3)=0

⇒ 3x+25=0 and x−3=0

⇒ x=

3

−25

and x=3

∴ We can see that roots given in question are correct.