Answer:
7x−3=7k,x=7k+3,k∈ℤ
Step-by-step explanation:
3x ≡ 2 (mod 7)
3 is a solution, since 3×3−2=7.
All solutions are 3+7ℤ
y=3x−2/7=3(x−3)+7/7=3(x−3)/7+1
7x−3=7k,x=7k+3,k∈ℤ
Answer:
a) P(2)=0.270
b) P(X>3)=0.605
c) P=0.410
Step-by-step explanation:
We know that customers arrive at a grocery store at an average of 2.1 per minute. We use the Poisson distribution:

a) In this case: 

Therefore, the probability is P(2)=0.270.
b) In this case: 

Therefore, the probability is P(X>3)=0.605.
c) We know that two customers came in in the first minute. That is why we calculate the probability of at least 5 customers entering the other 2 minutes.
In this case: 

Therefore, the probability is P=0.410.
Answer:This problem is about linear equations. We assume Dale drive X miles, and the total cost is $Y, then we can get:
Plan I: Y=38+0.11X
Plan II: Y=49+0.07X
When both plans cost the same, 38+0.11X=49+0.07X. We will get X = 275miles, and Y=$68.25
Step-by-step explanation: