Question

11) calcule as raízes da equação:
a) 5x²-20=0
b) √2/3x²=0
c) x²+x/5=0
d) 7x²-21=0
e) 2x²+5x=0
f) -x²+4x=0
Formula de bhaskara

Answer 1

É SÓ EQUACIONAR:

A) 5x²-20=0 > 5x²= +20 > x²=20/5 > x²= 4 > x= √4 = 2

B) √2/3x²=0 > √2/3x²=0

√2x²/3=0

2x/3=0

2x=0

x=0/2

x=0

C) X²+x/5=0

5x²+x=0

6x²=0

x²=0/6

x=√0

x= 0

D) 7x²-21=0

7x²=21

x²=21/7

x²=3

x=+-√3

E) 2x²+5x=0 X em evidencia

X(2x+5)

X'=0

X''=2x+5 = 2x=-5 x=-5/2

S[0,-5/3]

F) -x²+4x=0

-X(x-4)

X'=0

X''= x=4