Question

encontre a solução das equações a seguir em cada item: a) x²-5x=0 b) -4 x²+ 12x = 0 c) 6x² - 15x = 0 d) 2x²-8x = 0 e) -5x²+15x=0

Answer 1

Ola Gaby

a) x² - 5x = 0

x*(x - 5) = 0 

x1 = 0, x2 = 5

b) -4x² + 12x = 0

x² - 3x = 0
x*(x - 3) = 0

x1 = 0, x2 = 3

c)

6x² - 15x = 0

x*(6x - 15) = 0

x1 = 0, x2 = 5/2

d) 2x² - 8x = 0

x² - 4x = 0
x*(x - 4) = 0

x1 = 0, x2 = 4

e) -5x² + 15x = 0

x² - 3x = 0
x*(x - 3) = 0

x1 = 0, x2 = 3

Answer 2

a)x² - 5 x = 0
x( x - 5 ) = 0
x = 0
x - 5 = 0
x = 5
S = {0,5}
b)-4 x² + 12 x = 0
4 x(-1 x +  3 ) = 0
4 x = 0
x = 0/4
x = 0
-1 x + 3 = 0
-1 x = -3
x = -3/-1
x = 3
S = {0 , 3}
c)6 x² - 15 x = 0
3 x(2 x - 5 ) = 0
3 x = 0
x = 0/3
x = 3
2 x - 5 = 0
2 x = 5
x = 5/2
S = {5/2, 3}
d)2 x² - 8 x = 0
2 x(x  -  4 ) = 0
2 x = 0
x = 0/2
x = 0
x - 4 = 0
x = 4
S = {0, 4}
e) -5 x² + 15 x = 0
5 x (-1 x + 3)  = 0
5 x = 0
x = 0/5
x = 0
-1 x + 3  = 0
-1 x = - 3
x = - 3 / -1
x = 3
S = {0, 3 }