Question

va rog ajutati-ma e urgent va rog​

Answer 1

Uite câteva:

a)x²-5x+6=0

{a=1

{b=-5

{c=6

∆=b²-4ac=(-5)²-4•1•6=25-24=1

x1,2= - b +/- ✓∆ /2a

$x1 = \frac{ - b + \sqrt{delta} }{2a} = \frac{ - ( - 5) + 1}{2 \times 1} \\ x1 = \frac{5 + 1}{2} = \frac{6}{2} = 3 \\ \\ x2 = \frac{ - b - \sqrt{delta} }{2a} = \frac{ - ( - 5) - 1}{2 \times 1} \\ x2 = \frac{5 - 1}{2} = \frac{4}{2} = 2$

u)

$- x {}^{2} + x + 6 = 0$

{a=-1

{b=1

{c=6

∆=b²-4ac=1²-4•(-1)•6=1+24=25

x1,2= - b +/- ✓∆ /2a

$x1 = \frac{ - b + \sqrt{delta} }{2a} = \frac{ - 1 + \sqrt{25} }{2 \times ( - 1)} = \frac{ - 1 + 5}{ - 2} \\ x1 = \frac{4}{ - 2} = - 2 \\ \\ x2 = \frac{ - b - \sqrt{delta} }{2a} = \frac{ - 1 - 5}{ - 2} = \frac{ - 6}{ - 2} = 3$

t) -3x²-x+2=0

{a=-3

{b=-1

{c=2

∆=b²-4ac=(-1)²-4•(-3)•2=1+12•2=1+24=25

x1,2= - b +/- ✓∆ /2a

✓∆=✓25=5

$x1 = \frac{1 + 5}{ 2 \times ( - 3)} = \frac{ 6}{ - 6} = - 1 \\ x2 = \frac{1 - 5}{ 2 \times ( - 3)} = \frac{ - 4}{ - 6} = \frac{4}{6} {}^{(2} = \frac{2}{3}$

toate se rezolva la fel