Question

If a+b=7 & ab=10 so find value of a²+b²​

Answer 1

Answer:

, (a+b)=7, ab=10

Squaring both sides

⇒(a+b)2=72

⇒a2+b2+2ab=49

⇒a2+b2=49−2(10)

⇒a2+b2=29

Now,

(a−b)2=a2+b2−2ab

          =29−2(10)

          =29−20

          =9

∴a−b=9

                  =±3