Question

resolva as equações incompletas

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Answer 1

a)

5x^2-3125= 0

5x^2= 0+3125

5x^2= 3125

x^2= 3125/5

x^2=√625

x=25

b)

3x^2-81=0

3x^2= 0+81

3x^2= 81

x^2= 81/3

x^2= √27

x= 3√3

c)

-3x^2+27=0

-3x^2= 0-27

-3x^2=-27

x^2= -27/-3

x^2=√9

x= 3

d)

10x^2+100x=0

x(10x+100)=0

10x+100=0

10x=0-100

10x=-100

x=-100/10

x= -10

ou

x=0

e)

4(-x^2-1)=-5x^2+8

-4x^2-4= -5x^2+8

-4x^2+5x^2=8+4

x^2= √12

x= 2√2

f)

(x-7)(x+4)=x-28

x^2+4x-7x-28=x-28

x^2-3x-x-28+28=0

x^2-4x=0

x(x-4)=0

x-4=0

x=0+4

x=4

ou

x=0