a)x²-12x+35=0
a=1,b= -12, c= +35
∆ = (b)²-4ac
∆ =  (-12)² - 4 .(1) .(+35)
∆ = +144 -140
∆ = +4

x= -b+ou - √▲/2a
x= -(-12) + ou-√4/2.1
x=(+12+ ou - 2)/2
x¹= (+12 + 2)/2= +14/2= 7
x²= (+12-2)/2 = +10/2= 5
S= 7,5
vlw linda

Respostas

2014-05-23T16:20:51-03:00
X = -b ±√b² - 4.a.c
            2a
x = 12±√12
²-4.1.35
              2
x = 12±√144-140
              2
x = 12±√4
         2
x = 12±2
         2
x1= 10/2 = 5

x2= 14/2 = 7