Answer:
y=1
Step-by-step explanation:
2y+5y-7=0
Combine y: 7y-7=0
Move 7 over: 7y=7
Divide by 7:y=1
Answer:
a) 
b) 
Step-by-step explanation:
Previous concepts
The exponential distribution is "the probability distribution of the time between events in a Poisson process (a process in which events occur continuously and independently at a constant average rate). It is a particular case of the gamma distribution". The probability density function is given by:

And 0 for other case. Let X the random variable that represent "life lengths of automobile tires of a certain brand" and we know that the distribution is given by:

The cumulative distribution function is given by:

Part a
We want to find this probability:
and for this case we can use the cumulative distribution function to find it like this:

Part b
For this case w want to find this probability

We have an important property on the exponential distribution called "Memoryless" property and says this:
On this case if we use this property we have this:
We can use the definition of the density function and find this probability:

Answer:
d) not proportional
Step-by-step explanation:
the rate of change between the first two pairs of x-and-y values is 12/3, between the second pair it is 21/3, and 15/3 between the last pair
4, 7, and 5 are all different values so there is not one constant of proportionality
Approximately 59% of the video
10/17 as a decimal is 58.82, so rounded up, it would be 59^