Let x be Mark's dollars... x + 5 = Austin's dollars....Brainliest?....
b must be equal to -6 for infinitely many solutions for system of equations
and 
<u>Solution:
</u>
Need to calculate value of b so that given system of equations have an infinite number of solutions

Let us bring the equations in same form for sake of simplicity in comparison

Now we have two equations

Let us first see what is requirement for system of equations have an infinite number of solutions
If
and
are two equation
then the given system of equation has no infinitely many solutions.
In our case,

As for infinitely many solutions 

Hence b must be equal to -6 for infinitely many solutions for system of equations
and
the mean is adding all them together and dividing by how many there are
2+3+5+6+1+10 = 27
there are 6 numbers so 27/6 = 4.5
mean = 4.5
Having The Lack Of Information, We Can Only Give You An Equation.
So:
Quotient = Division.
R / 12 Is The Equation.
(If This Is Not What You Need, Put In More Info, And I Can Solve It. ;) <span />