Let x be the unknown number.
The sum of x and seven hundred is 
Ten thousand times this sum is 
Slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept.
The first step is to find the slope using the provided coordinates (-2, 6) and (2, 14). We can do that using the y1 - y2 / x1 - x2, like so:
6 - 14 / -2 - 2
-8 / -4
2
The slope is two, so we immediately know the answer is either A or B.
Now, plot the two points on graphing paper and determine where the line intersects the y-axis to find the y-intercept...
My graph shows the line intersecting the y-axis at 10, therefore the correct answer is:
y = 2x + 10
1.
"The spending limit on John’s credit card is given by the function f(x)=15,000+1.5x"
means that if the monthly income of John is $ 5,000 ,he can spend at most
f(5,000)=15,000+1.5*5,000=15,000+ 7,500=22, 500 (dollars)
Or for example
if Johns monthly income is $8,000, then he can spend at most
f(8,000)=15,000+1.5*8,000=15,000+ 12,000=27,000 (dollars)
2.
Now, assume that the maximum amount that John can spend is y.
Then, y=15,000+1.5x
we can express x, the monthly income, in terms of y by isolating x:
y=15,000+1.5x
1.5x = y-15,000
X=y-15,000/1.5
thus, in functional notation, x, the monthly income, is a function , say g, of variable y, the max amount:
X=g(y) y-15000/1.5
since we generally use the letter x for the variable of a function, we write g again as:
G (x) x-15000/1.5
tells us that if the maximum amount that John can spend is 50,000 $, then his monthly income is 23,333 $.
3.
If John's limit is $60,000, his monthly income is
G(600,000)=60,000-15,000/ 1.5=45,000/1.5 =30,000
dollars.
Answer: $ 30,000
Remark: g is called the inverse function of f, since it undoes what f does.
instead of g(x), we could use the notation
a. because to divide 6 1/4 and 3 you need to make the improper fraction a mixed number so the equation is 25/4 / 3/1 then you get the recipricol of 3 witch is 1/3 then you multiply 1/3 x 25/4 whitch is 25/12=2 1/12
