The one that doesn't have an "x" repeated, that is an X-REPEAT
notice, the pair is just an x,y pair.. .so if the "x" is repeated, is NOT a function
let's see
Answer:
Therefore the required ways are =190
Step-by-step explanation:
Combination: Combination is the number of selection of items from a collection of items where the order of selection does not matter.
Total number of smartphones =22
Defective phone = 2
Non defective phone = (22-2) =20
The control inspector randomly test 4 smartphones of which 2 are defective.
Non defective phone = 2
The ways to select 2 non defective phone is

The ways to select 2 defective phone is= 
Therefore the required ways are = (190×1) =190
ANSWER
No real roots.
The roots are complex or imaginary.
EXPLANATION
The quadratic equation

has discriminant,

If the discriminant is less than zero , then the quadratic equation has no real roots.
The given discriminant is -9.
Since -9 is less than zero, it means the quadratic equation has complex or imaginary roots.