Question

1. If a² +b^61 and ab = 30, then a+b = ?​

Answer 1

Step-by-step explanation:

Given, (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

Answer 2

Step-by-step explanation:

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

Example ↑

✪============♡============✿

$\huge \pink{✿} \red {C} \green {u} \blue {t} \orange {e} \pink {/} \red {Q} \blue {u} \pink {e} \red {e} \green {n} \pink {♡}$