Question

2 × ao quadrado + 7 × = 0

Answer 1

Δ = b^2 - 4.a.c 
Δ = 7^2 - 4 . 2 . 0 
Δ = 49 - 4. 2 . 0 
Δ = 49

Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (-7 + √49)/2.2   
x'' = (-7 - √49)/2.2

x' = 0 / 4   
x'' = -14 / 4

x' = 0   
x'' = -3,5

Answer 2

2x² + 7x = 0

x • (2x + 7 ) = 0

x= 0

2x + 7 = 0

2x = 0 - 7

2x = - 7

x= - 7/2

S= ( 0 , - 7/2)