Question

Emaan charges a fixed amount for a bracelet, with an additional charge for each charm a customer adds to the bracelet. Write a linear function / thatEmaan can use to find the price of a bracelet.Charms 5 10 20 30Cost ($) 110 180 320 460A f(x)=2x + 100B. f(x) = 14x + 40C. f(x) = 6x + 80OD. fx)=12x + 60

Answer 1

ANSWER :

B. f(x) = 14x + 40

EXPLANATION :

We can let x = number of charms and y = cost as points (x, y)

Using two-point formula :

$y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)$

with two points from the given, (5, 110) and (20, 320)

$\begin{gathered} y-110=\frac{320-110}{20-5}(x-5) \\ y-110=14(x-5) \\ y-110=14x-70 \\ y=14x-70+110 \\ y=14x+40 \\ \text{ Change y into f\lparen x\rparen} \\ f(x)=14x+40 \end{gathered}$