This equation does not have any solution since determinant <0
i.e.,D=b^2-4ac
=2^2-4×1×7
=4-28
=-24
i.e.,is less than 0
Answer:
approx 193200
Step-by-step explanation:
As known for normal distribution is correct the rule 95.4% of the results are situation within mean+-2*s ( where s is a standard deviation)
So the border is 100+-2*15=70 and that is approx=67.
95.4% of 84000000 citizens are= 8 400 000*0.954=8013600 persons
So the residual number of the citizens =8400000-8013600=386400 citizens
Because of the simmetry of normal distribution to find the number of the citizens that have IQ below 67 we have to divide 386400 by 2.
N=386000/2=193200
The r variable outside the parentheses can multiply both the numbers in the parentheses.
This called distributing the r. We are using the distributive property.
The distributive property states that a(b + c) = ab + ac.
r(18 - 3) = 18r - 3r
So, (r * 18) - (r * 3) is the answer.
