I think only the first two
Let 'x' be the problems worth 2 points.
Let 'y' be the problems worth 3 points.
Since, there are 38 total problems.
So, 
(equation 1)
x = 38-y
Since, a perfect score is 100 points.
So, 
(equation 2)
Substituting the value of 'x', we get
y = 24
x+y = 38
x = 38-24 = 14
So, 14 problems are worth 2 points and 24 problems are worth 3 points.
A function f(x) has solutions if we can find a value to plug in that leads to 0. In other words, there are solutions to f(x) = 0. Another term for "solution" is "root" or "x intercept"
An exponential function may cross the x axis at one point only. Though there are plenty of cases when there are no solutions at all. For instance, in the case of f(x) = (2^x) + 10
The right hand side will never be equal to zero no matter what you plug in for x. The graph will never cross the axis.
To answer your question, yes it is possible to have an exponential equation to have no solutions.
For this case we convert the mixed numbers to fractions:
Dwight:
Mike:
It is observed, that in fact, Mike takes more time to travel the road.
We subtract to know how much more time it takes Mike:
So, Mike takes 
hours more than Dwight to walk the road.
Answer:
Mike takeshours longer than Dwight to walk the road.
Answer:
12-x*3
Step-by-step explanation:
