Question

Resolver as seguintes equações incompletas do 2 Grau ...

a) (Y+5)² = 9
b)(Y-5)² =9
c) (2x -1)²= 81
d)100x²-1=0
e) 49x²-1=0

Answer 1

a) y² + 10y + 25 - 9 = 0
y² + 10y + 16 = 0
Δ = b² - 4 a c
Δ= (10)² - 4 .1 . 16 = 100 - 64= 36
x = - 10-6 /2 =-16 /2 = 8
x= -10 + 6 /2 = - 4 /2 = -2
b)y² - 10y +25  -9 = 0
 y² -10y +16 = 0
Δ= 36
x = 10 +6 / 2 = 8
x = 10 - 6 / 2 =2
d) 100x² = 1
x² = 1 / 100 =√ 1 / 100 
x = 1 / 10
e) 49x² = 1 =
 x² =√ 1 / 49
x = 1 / 7