Question

por favor alguém pode resolver essas questões, Eq do
2. Grau Para Mim ?
${5x }^{2} - 3x - 2 = 0$
${x}^{2} - 2x - 8 = 0$
${x}^{2} - 10x + 25 = 0$
${x}^{2} - 6x + 9 = 0$

Answer 1

${5x}^{2} - 3x - 2 = 0$
a= 5. b=-3 c=-2
∆=
${b}^{2} - 4 \times a \times c$
∆=
${ - 3}^{2} - 4 \times 5 \times ( - 2)$
∆= 9- 20×(-2)
∆= 9 + 40
∆= 49

x'= -b+√∆÷2×a
x'= -(-3)+√49÷2×5
x'= 3+7/10
x'= 10/10
x'= 1

x"= -b-√∆÷2×a
x"= -(-3)-√49÷2×5
x"= 3-7÷10
x"= -4/10
x"= -2/5



${x}^{2} - 2x - 8 = 0$
a=1. b=-2. c=-8.
∆= b^2 - 4×a×c
∆= (-2)^2 - 4×1×(-8)
∆= 4 + 32
∆= 36

x'= -b+√∆÷2×a
x'= -(-2)+√36÷2×1
x'= 2+6÷2
x'= 8÷2
x'= 4

x"= -b-√∆÷2×a
x"= -(-2)-√36÷2x1
x"= 2-6÷2
x"= -4÷2
x"= -2




${x}^{2} - 10x + 25 = 0$
a=1. b=-10. c=25.
∆=b^2-4×a×c
∆= (-10)^2 - 4×1×25
∆= 100 - 100
∆= 0

x= -b+-√∆÷2×a
x= -(-10) +-√0÷2×1
x= 10÷2
x= 5




${x}^{2} - 6x + 9 = 0$
a=1. b=-6. c=9
∆= b^2-4×a×c
∆= (-6)^2 - 4×1×9
∆= 36 - 36
∆=0

x= -b+-√∆÷2×a
x= -(-6)+-√0÷2×1
x= 6÷2
x= 3