Question

responda

a- x²-4x=0
b- x²-3x+2=0
c- x²-7x+12=0

Answer 1

a)

x²-4x=0

x(x-4)=0

x=0

x-4=0

x=4

S={0, 4}

b)

x²-3x+2=0

∆=(-3)²-4(1)(2)

∆=9-8

∆=1

x':

$x = \frac{ - ( - 3) + \sqrt{1} }{2(1)} \\ \\ x = \frac{ 3 + 1}{2} = \frac{ 4}{2} = 2$

x'':

$x = \frac{ - ( - 3) - \sqrt{1} }{2(1)} \\ \\ x = \frac{3 - 1}{2} = \frac{2}{2} = 1$

c)

x²-7x+12=0

∆=(-7)²-4(1)(12)

∆=49-48

∆=1

x':

$x = \frac{ - ( - 7) + \sqrt{1} }{2(1)} \\ \\ x = \frac{7 + 1}{2} = \frac{8}{2} = 4$

x'':

$x = \frac{ - ( - 7) - \sqrt{1} }{2} \\ \\ x = \frac{7 - 1}{2} = \frac{6}{2} = 3$

S={3, 4}

Answer 2

Agora foi, espero ajudar