Question

Stiind ca a+b=8 si a•b=12 calculati 1/a+1/b​

Answer 1

1. a+b=8
2. a×b=12

din 1 => a=8-b=> (8-b)×b=12=>8b-b^2=12=>-b²+8b-12=0

delta= 64-48= 16

b1= (-8+4):(-2)= 2

b2= (-8-4):(-2)= 6

a1= 8-b1= 8-2=6

a2= 8-b2=8-6=2