Question

Utilizando a fórmula de Báscara, resolve as equações:
a) x²+8x-9=0
b) 2x²+12x-14=0
c) 2x²-10x+8=0

Answer 1

Resposta

a)x²+8x-9=0

A=1 b=8 c=-9

¤=b² -4.a.c

¤=8²-4.1.-9

¤=64+36

¤=100

X=-b+_V¤/2.A

X=-(8)+_V100/2.1

X=-8+_10/2

X'=-8+10/2

X'=2/2

X'=2

X"=-8-10/2

X"=-18/2

X"=-6

b) 2x²+12x-14=0

A=2 b= 12 c=-14

¤=b²-4.a.c

¤=12²-4.2.-14

¤=144+112

¤=256

X=-b+_V¤/2.A

X=-(12)+_V256/2.2

X=-12+_16/4

X'=-12+16/4

X'=4/4

X'=1

X"-12-16/4

X"=-28/4

X"=-7

c) 2x²-10x+8=0

¤=b²-4.a.c

¤=-10²-4.2.8

¤=100-64

¤=36

X=-b+_V¤/2.A

X=-(-10)+_V36/2.2

X=10+_6/4

X'=10+6/4

X'=16/4

X'=4

X"=10-6/4

X"=4/4

X"=1

¤=delta

V=raiz quadrada