Question

Problema 8 daca poate cineva la ora asta :))​

Answer 1

√(3-x)+√(5x+9)=4

√(3-x)=4-√(5x+9)

3-x=16-8√(5x+9)+5x+9

3-x=25-8√(5x+9)+5x

8√(5x+9)=25+5x-3+x

8√(5x+9)=22+6x

4√(5x+9)=11+3x

16×(5x+9)=121+66x+9x²

80x+144=121+66x+9x²

80x+144-121-66x-9x²=0

14x+23-9x²=0

-9x²+14x+23=0

9x²-14x-23=0

x={-(-14)±√[(-14)²-4×9×(-23)]}/(2×9)

x=[14±√(196+828)]

x=(14±√1024)/18

x=(14±32)/18

x=(14+32)/18 => 46/18=23/9

x=(14-32)/18 => -18/18=-1

√(3-23/9)+√(5×23/9+9)=4

√[3-(-1)]+√[5×(-1)+9]=4

5,(3)=4

4=4

x=-1 ✔

Answer 2

Explicație pas cu pas: