7h+3s=27.95 subtract 7h from both sides
3s=27.95-7h divide both sides by 3
s=(27.95-7h)/3
Then we are told:
5h+4s=23.4, using s found above makes this equation become:
5h+4(27.95-7h)/3=23.4 multiply both sides by 3
15h+4(27.95-7h=70.2 perform indicated multiplication on left side
15h+111.8-28h=70.2 combine like terms on left side
-13h+111.8=70.2 subtract 111.8 from both sides
-13h=-41.6 divide both sides by -13
h=$3.20
Consider the exponential function 
By definition, the domain of a function is the set of input argument values for which the function is real and defined.
Let we take
then 
then 
then 
If we chose larger values of x, we get larger function values.
For example, If we take 


Thus if we choose smaller and smaller values of x. the f unction values will be smaller and smaller functions.
Thus the domain of the function is the set of all real numbers.
Thus the range is limited to the set of positive real numbers. That is, 
If we choose larger values of x, we will get larger function values, as the function values will be larger powers of 2.
If we choose smaller and smaller x values, the function values will be smaller and smaller fractions.
Answer:
A rate of change is a rate that describes how one quantity changes in relation to another quantity.