Equações do 2º Grau
1.
Resolva as seguintes equações do 2º grau, sendo o conjunto U = R:
a) x2 + 7x = 0 S = {0, -7}
b) -3x2
+ 9x = 0 S = {0, 3}
c) 2x2
+ 3x = 0 S = {0, 3/2}
d) (y
+ 5)2 = 2x + 25 S = {0, - 8}
d) x2
+ 9x = 0 S = {0,-9 }
e) (y
+ 5)(y – 1) = 2y – 5 S = {0, - 2}
e) y2
– 10 = 0 S = { }
f) 2x2
+ 50 = 0 S = { }
g) -5r2
+ 20 = 0 S = {-2, 2}
h) 9a2
= 25 S = {-5/3, 5/3}
i) (b
+ 6)(b – 4) = 2b + 12 S = {-6, 6}
j) 5y2-
9y – 2 = 0 S = {2, -1/3}
k) x2 – 9x + 20 = 0 S = {4, 5}
l) y2 + 9y + 14 = 0 S = {-2, -7}
m) b2
– 3b – 10 = 0 S = {-2, 3}
n) 2y2
+ 7y + 6 = 0 S = {-2, -3/2}
o) 4y2
– 4y + 2 = 0 S = { }
p) 5t2
– 9t + 4 = 0 S = {1, 4/5}
q) 21m2
–26x + 8 + 0 S = {2/3, 4/7}
r) 4p2
– 20p + 25 = 0 S = {5/2}
s) x(x
+ 3) = 5x + 15 S = {-3, 5}
t) 2(a
– 5) = a2 – 13 S = {-1, 3}
u) S = {-1/3, -1}
v) S = {2/3, -4/3}
w) x2 + 14x + 49 = 0 S = {-7}
x) 9y2 – 24y + 16 = 0 S = {4/3}
y) (3y + 2)(y – 1) = y(y + 2) S = {2, -1/2}
z) m2(m
– 1) = m(m + 1)(m + 5) S = {0, -5/7}