Question

Resolva as equações. A) X2+5x+4=0. B)X2-7x-12=0
C)6x2-13x+6=0
D)-x2-x+30=0
E)X2+5x-10=0

Answer 1

A) x²+5x+4=0

(√x²+√4)
x+2=0
x=-2

B) x²-7x-12=0

X= -b+-√b²-4ac/2a
X= -(-7)+-√(-7)²-4.(1).(12)/2.(1)
X= 7+-√49-48/2
X=7+-√1/2
X1=7+1/2 X1=8/2 X1=4
X2=7-1/2 X2=6/2 X2=3

C) Nao entendi a equação, se puder repetir...

D) -x²-x+30=0

X= -b+-√b²-4ac/2a
X= -(-1)+-√(-1)²-4.(-1).(30)/-2
X=1+-√1+120/-2
X=(1+-√1+120/-2).(-1)
X=-1+-√1+129/2
X=-1+-√130/2
X=-1+-11,40/2
X1=-1+11,40/2 X1=10,40/2 X1=5,20
X2=-1-11,40/2 X2=-12,40/2 X2=6,20

E) x²+5x-10=0

X= -b+-√b²-4ac/2a
X= -(+1)+-√(5)²-4.(1).(-10)/2.(1)
X= 1+-√25+40/2
X= 1+-√65/2
X=1+-8,06/2
X1=1+8,06/2 X1= 9,06/2 X1= 4,53
X2= 1-8,06/2 X2=7,06/2 X2=3,53