Question

Escreva a equação ax2 + BX + C = 0 quando:
a) a= 1, b= 6, c= 9
b) a= 4, b= -6, c=2
c) a=4, b=0, c= -25
d) a= -21, b=7, c=0​

Answer 1

Resposta:

a) $x=-1,125$

b) $x=-1$

c) $x=3,125$

d) $x=0$

Explicação passo-a-passo:

Equação: $ax2+bx+c=0$

a) $a=1,b=6,c=9$

$1\times x \times2 +6\times x+9=0\\2x+6x+9=0\\8x+9=0\\8x=0-9\\x=\frac{-9}{8}\\x=-1,125$

b) $a=4,b=-6,c=2$

$4\times x \times2+ (-6)\times x+2=0\\8x+(-6x)+2=0\\8x-6x=0-2\\2x=-2\\x=\frac{-2}{2}\\x=-1$

c) $a=4,b=0,c=-25$

$4x\times2+0x+(-25)=0\\8x-25=0\\8x=25\\x=\frac{25}{8}\\x=3,125$

d) $a=-21,b=7,c=0$

$(-21x)\times2+7x+0=0\\-42x+7x=0\\-35x=0\\x=\frac{0}{35}\\x=0$