Question

Resolva as equações incompletas de 2° grau :

a)5x²+25x=0
b)x² - 49x=0
c)4x² - 16x=0
d)5x² - 125=0
e)x² - 5=20
f)4x² - 64=0

Answer 1

a) x(5x - 25)=0
x=0

5x - 25=0
5x = 25
x=25/5
 x=5
 S{0,5}

b) x(x - 49)=0
x=0

x - 49 = 0
x = 49
S{0,49}

c)x(4x - 16) = 0
x=0

4x-16=0
4x=16
x=16/4 =4
S{0,4}

d)5x²=125
x²=125/5 = 25
x = 5

e)x²=20+5
x²=25
x=5

f)4x²=64
x²=64/4 =16
x²=16
x=4