Answer:
your answer will bw the option A.
Step-by-step explanation:
Answer:
64
Step-by-step explanation:
x + 5(x + 2)
Distribute
x + 5x+10
Combine like terms
6x+10
Let x = 9
6(9) +10
54+10
64
The number (x) that is (=) 10 less than (-) 6
x = 6 - 10 Subtract
x = -4
Answer:
The probability that a randomly chosen light bulb will last less than 900 hours is 0.1587.
Step-by-step explanation:
The life span of these light bulbs is normally distributed with a mean of 1000 hours and a standard deviation of 100 hours
Mean = 
Standard deviation =
We are supposed to find the probability that a randomly chosen light bulb will last less than 900 hours.i.e. P(x<900)
So, 

Z=-1
P(x<900)=P(z<-1)=0.1587
Hence the probability that a randomly chosen light bulb will last less than 900 hours is 0.1587.