50. Model with mathematics. A water company charges residential customers a quarterly flat fee of
$25 for up to 5000 gallons of water. The company
charges $10 per thousand for the first 10,000
gallons of water after the minimum allowance. The
next 10,000 gallons is $5 per thousand. All other
consumption over 25,000 is $2.50 per
thousand.
a. Write a piecewise function w(x) that can be
used to determine a customer's quarterly bill for
using x gallons of water.

i dont know sorry

step-by-step explanation:

4a. is 3 miles every hour

4b. is 1/3 of an hour per mile

step-by-step explanation:

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form