Question

calcule:

a) x²–6x+8

b) –x²+2x+3​

Answer 1

A) ∆= 1² - 4×(-6)×8

∆= 1 + 192

∆= 193

X= 4 ± √193/ 2×1

X= 4 + 13,8 / 2

X= 17,8 /2

X1= 8,9

X2= -4,9

B) –x²+2x+3​

∆= 2²-4×(-1)×3

4+ 12

∆=16

X= -2±√16/2×(-1)

X= 2 + 4 /-2

X1= -3

X2= -2 /-2

X2= 1