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-When making a telephone call using a calling card, a call lasting 3 minutes costs $\$ 1.15$. A call lasting 13 minutes costs $\$ 3.65$. Let $y$ be the cost of making a call lasting $x$ minutes using a calling card. Write a linear equation that models the cost of making a call lasting $x$ minutes.
A) $y = 0.25 x + 0.4$
B) $y = 0.25 x - 9.35$
C) $y = - 0.25 x + 1.9$
D) $y = 4 x - \frac { 217 } { 20 }$

Question

Quizplus · Accepted Answer

To find the correct linear equation, we can use the given data points: (3, 1.15) and (13, 3.65). The slope $m$ of the line is calculated as $\frac{3.65 - 1.15}{13 - 3} = \frac{2.5}{10} = 0.25$. To find the y-intercept $b$, we can use one of the points: $1.15 = 0.25(3) + b$, solving for $b$ gives $b = 1.15 - 0.75 = 0.4$. Therefore, the equation is $y = 0.25x + 0.4$.

Solve Hat -When Making a Telephone Call Using a Calling $1.15\$ 1.15$1.15

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-When Making a Telephone Call Using a Calling $\$ 1.15$