Answer:
$81.60
Step-by-step explanation:
A 20% markdown means that the chairs were sold at 80% of the original cost.
Original cost = $102
markdown = 20%
Cost after markdown = original cost* (1-markdown)
Cost after markdown = 102 *(1 - 0.20)
= 102*0.80
= 81.6
Therefore, the 4 chairs were sold at a total cost of $81.60
Answer: 3rd graph
Explanation: In order to determine which graph shows a downward or negative slope, we need to be able to look at each of the graphs and determine which line is decreasing when going from left to right.
Notice that the 3rd graph is the only graph with a downward
or negative slope which means that this is our answer.
F(x) = 4x - 9
let f(x) = y, this implies that x = f⁻¹(y)
y = 4x - 9 Let us solve for x.
4x - 9 = y
4x = y + 9
x = (y + 9)/4
Recall that x = f⁻¹(y),
x = (y + 9)/4
f⁻¹(y) = (y + 9)/4
That means that for f⁻¹(x)
f⁻¹(x) = (x + 9)/4
Hope this explains it.