Question

if a+b=12 and ab=27 then find a2+b2

Answer 1

Answer:

for this

use (a+b)²

we know

(a+b)² = a² + b² +2ab

put the given values

(12)² = a² + b² + 2(27)

144 = a² +b² +54

a² + b² = 90

Answer 2

Answer:

a+b=12

a=12-b

ab=27

(12-b)b=27

12b-b2=27

b2-12b+27=0

b2-9b-3b+27=0

b(b-9)-3(b-9)=0

(b-3)(b-9)=0

b=3,9

if b=3

a+3=12

a=9

and if b=9

a=3