Question

Quais as raizes das equações : (cálculo)

1) x2-14x+48=0
2) x2-5x+6=0
3) x2+2x-8=0
4) x2+3x-28=0

Answer 1

1) 6 e 8
2)2 e 3
3)-4 e 2
4) 4 e -7

Answer 2

1) x²-14x+48=0

a= 1
b= -14
c= 48

∆= b²-4ac
∆= (-14)² -4 .1 .48
∆= 196 - 192
∆= 4

-b +- √∆ / 2a
-(-14) +- √4 / 2 .1
14 +- 2 / 2
x'= 14+2 /2= 16/2= 8
x''= 14-2 /2= 12/2= 6
S= {8, 6}


2) x²-5x+6=0

a= 1
b= -5
c= 6

∆= b² -4ac
∆= (-5)² -4 .1 .6
∆= 25-24
∆= 1

-b+-√∆ /2a
-(-5) +- √1 /2.1
5 +-1 /2
x'= 5+1 /2= 6/2=3
x''= 5-1 /2= 4/2=2
S= {3, 2}


3) x²+2x-8=0

a= 1
b= 2
c= -8

∆= b²-4ac
∆= 2² -4 .1 .-8
∆= 4+32
∆= 36

-b +-√∆ /2a
-2 +-√36 /2.1
-2 +-6/2
x'= -2+6/2= 4/2= 2
x''= -2-6/2= -8/2= -4
S= {2, -4}


4) x²+3x-28=0

a= 1
b= 3
c= -28

∆= b²-4ac
∆= 3²-4 .1 .-28
∆= 9+112
∆= 121

-b+-√∆ /2a
-3+-√121 /2.1
-3+-11 /2
x'= -3+11/2= 8/2= 4
x''= -3-11/2= -14/2= -7
S= {4, -7}