aplication

1. modulus inequalities
modulus of x, written |x|, is defined as x, if x ≥ 0 and – x, if x < 0.
Find solution of |3x-5| < |x+9|

2. equation
find solution of system y = 4x2–5x+6
y = 3x2-2x+4

3. integers exponent
simplify: x-3.y-3

4. discriminant
the term b2-4ac in quadratic formula is called discriminant.
find of the quadratic equation 25x2-30x+9=0

5. the quadratic function
if ax2+bx+c=0 is a quadratic equation, then the function f(x) = ax2+bx+c is called a quadratic function.