Question

resolva a seguinte equação do 2 grau
A] x²-7x = 0
B]x²+5x = 5x=0
C]4x²-9x=0
D]3x²+5x=0
E]4x²-9x=0
F]5x²+x=0
G]x²+x=0
H]7x²-x=0
I]2x²=7x
J]2x²=8x

Answer 1

A] x²-7x = 0
a= 1, b= -7, c= 0

∆= b²-4.a.c
∆= (-7)² - 4.1.0
∆= 49

x= -b±√∆ /2.a

x'= 7+7/2.1
x'= 14/2
x'= 7

x"= 7-7/2
x"= 0/2
x"= 0

B]x²+5x = 5x=0
x²+5x-5x=0
x² = 0
√x² = √0
x= ±0

C]4x²-9x=0
a= 4, b= -9, c= 0

∆= (-9)² -4.4.0
∆= 81

x= -b±√∆ /2.a

x'= 9+9/2.4
x'= 18/8
x'= 2,25

x"= 9-9/8
x"= 0/8
x"= 0

D]3x²+5x=0
a= 3, b= 5, c= 0

∆= 5² - 4.3.0
∆= 25

x= -b±√∆ /2.a

x'= -5+5/2.3
x'= 0/6
x'= 0

x"= -5-5/6
x"= -10/6
x"= -5/3

E]4x²-9x=0
a= 4, b= -9, c= 0

∆= (-9)² - 4.4.0
∆= 81

x= -b±√∆ /2.a

x'= 9+9/2.4
x'= 18/8
x'= 2,25

x"= 9-9/8
x"= 0/8
x"= 0

F]5x²+x=0
a= 5, b= 1, c= 0

∆= 1² - 4.5.0
∆= 1

x= -b±√∆ /2.a

x'= -1+1/2.5
x'= 0/10
x'= 0

x"= -1-1/10
x"= -2/10
x"= -1/5

G]x²+x=0
a= 1, b= 1, c= 0

∆= 1² - 4.1.0
∆= 1

x= -b±√∆ /2.a

x'= -1+1/2.1
x'= 0/2
x'= 0

x"= -1-1/2
x"= -2/2
x"= -1

H]7x²-x=0
a= 7, b= -1, c= 0

∆= (-1)² - 4.7.0
∆= 1

x= -b±√∆ /2.a

x'= 1+1/2.7
x'= 2/14
x'= 1/7

x"= 1-1/14
x"= 0/14
x"= 0

I]2x²=7x
2x² - 7x = 0
a= 2, b= -7, c= 0
∆= (-7)² - 4.2.0
∆= 49

x= -b±√∆ /2.a

x'= 7+7/2.2
x'= 14/4
x'= 3,5

x"= 7-7/4
x"= 0/4
x"= 0

J]2x²=8x
2x² - 8x = 0
a= 2, b= -8, c= 0

∆= (-8)² - 4.2.0
∆= 64

x= -b±√∆ /2.a

x'= 8+8/2.2
x'= 16/4
x'= 4

x"= 8-8/4
x"= 0/4
x"= 0

Bons estudos! :)