Answer:
Total number number of cars which do not have defects = 539
and 21 are defected out of 560 i.e. 560 - 539 = 21
Step-by-step explanation:
Total cars checked by Car factory = 320
Number of defected cars = 12
The number of cars which do not have defects = 320 - 12 = 308
Total Number of cars = 560
So the equation becomes
⇒
⇒
⇒
Therefore, total number number of cars which do not have defects = 539
and 21 are defected out of 560 i.e. 560 - 539 = 21
This is a way to factoring trinomials (there exist different equivalent methods).
Multiply the trinomial but the term accompanying . This is the second line. Then, you could take the square of the
, ant try to create a factor () () that will correspond to the expression in the second line. That is, we want
In ? we put the corresponding numbers that, if we multiply them we will obtain 42, and if we add them we will obtain 13. This numbers are 6 and 7. Then, we have
The last step is divide by the number that we multipy in the first step.