Răspunsuri

2014-09-10T18:20:24+03:00
4x²-7-9=0

4x²-16=0

(2x-4)(2x+4)=0

2x-4=0   ∧  2x+4=0
2x=4           2x=-4
x=2                 x=-2
  • Utilizator Brainly
2014-09-10T18:21:52+03:00
4x²-7-9=0
4x²-16=0/+16
4x²=16/:4
x²=4
x∈{ 2, -2}