Smith Automotive needs to hire a new mechanic. They decide to place an ad in the Springfield Herald. A classified ad in the Springfield Herald costs
$45 for the first five lines. There is a charge of $5 for each additional line.

y = 45 + 5(x - 5)

where y is the total cost of the ad, and x is the total number of lines in the ad

Step-by-step explanation:

Let x = number of lines in the ad

Let y = total cost

If the cost of the ad is $45 for the first 5 lines and $5 for each additional line then the expression for the total cost of the ad is:

y = 45 + 5(x - 5)

equation: y = 5(x-5) + 45

Explanation:

Here "y" represents the total money earned. "x" represents the earning from additional line. the constant variable is "45" and does not change.

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