Question

a+b=-7 ab=10 find a,b

Answer 1

Answer:

Given, (a+b)=7, ab=10

Squaring both sides

⇒(a+b)

2

=7

2

⇒a

2

+b

2

+2ab=49

⇒a

2

+b

2

=49−2(10)

⇒a

2

+b

2

=29

Now,

(a−b)

2

=a

2

+b

2

−2ab

=29−2(10)

=29−20

=9

∴a−b=

9

=±3