Answer:
-$407
-tax:6%
407 times 6 divided by 100
413/100
4.13
407 plus 4.13
$411.13
Answer:
the graph will describe 13x+15 if the cost per audio book goes up by $1.00.
Step-by-step explanation:
This happens because the coefficient to x is 12 before the change. If the change is the cost per audio book going up by one dollar, the coefficient changes to 13. The initial joining fee is the same ($15.00).
7x + 14 + 3x + 15 = 14x + 14 + 2
10x + 14 = 14x + 16
14 - 16 = 14x - 10x
-2 = 4x
X = - 2/4
X = - 1/2 OR X = - 0.5
slope = - 
calculate the slope m using the gradient formula
m= (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (- 3, 6)
m =
=
= - 