a) 1 / b + 2 * (a * a + c) = 5
Hoặc : 1 / 2 * (sqr(a) + c) = 5
b) k * k + (x + 1) * (x + 1) <> (k + 2)
Hoặc : sqr(k) + sqr(x + 1) <> (k + 2)
c) 8 * x - 7 > 1
d) b * b - 4 * a * c >= 0
Hoặc : sqr(b) - 4 * a * c > = 0
e) (1 / (n * 1))/ (1 / (n + 1)) * (1 / (n + 2)) < 0.01
f) sqrt(2 * x + 3) <= 25 * y