Question

11. Resolva as equações a) 3x2 -75 = 0 b) x2 – 5x =0 c) x2 +8x – 9 = 0 d) x2 = 0

Answer 1

Resposta:

Explicação passo a passo:

3x²-75=0

3x²=0+75

3x²=75

x²=75/3

x²=25

x=√25

x=+5

x=-5

S={-5,5}

x²-5x=0

x(x-5)=0

x=0

x-5=0

x=0+5

x=5

S={0,5}

x²+8x-9=0

a=1

b=8

c=-9

x=-8+-V8²-4.1.-9/2.1

x=-8+-V64+36/2

x=-8+-V100/2

x=-8+-10/2

x'=-8+10/2=2/2=1

x''=-8-10/2=-18/2=-9

S={-9,1}

x²=0

x=√0

x=0

S={0}