Question

1. Rezolvaţi în R ecuatia:
a)x²-144=0
b) 5x²+7x=0;
c) 3x² + 5x+2 = 0
d) x²+10x+9=0​

Answer 1

Răspuns:

a) x1=12 , x2=-12

b) x1=0 , x2=-7/5

c)x1=-2/3 , x2=-1

d) x1=-1 , x2=-9

Answer 2

Explicație pas cu pas:

a)

x²-144=0

x²=144

x²=144

x=±12

x=±12

x=-12

x=12

x1=-12 , x2=12

b)

5x²+7x=0

x×(5x+7)=0

x=0

x= - 7 supra 5

x1= - 7 supra 5 , x2=0

forma alternativa:

x1= - - 1,4 , x2=0

c)

3x²+5x+2

3x²+3x+2x+2

3x²+3x+2x+2

3x×(x+1)+2x+2

3x×(x+1)+2x+2

3x×(x+1)+2(x+1)

3x×(x+1)+2(x+1)

(x+1)×(3x+2)

d)

x²+10x+9=0

x²+9x+x+0=0

x²+9x+x+0=0

x×(x+9)+x+9=0

x×(x+9)+x+9=0

(x+9)×(x+1)=0

(x+9)×(x+1)=0

x+9=0

x+1+0

x+9=0

x+1=0

x=-9

x=-1

x=-9

x=-1

x1=-9 , x2=-1

succes in continuare!