Question 86faf

Sep 8, 2017

$158$ minutes

Explanation:

Carlos pays a monthly fee of $6. In a mathematical function, this would be represented by a constant of $6$. He also pays $8$cents, or $0.08, per minute spoken. If $x$ were the number of minutes spoken, this would be represented by $0.08 x$.

Overall, Carlos' long distance bill can be represented by the function:

$f \left(x\right) = 0.08 x + 6$; where $f \left(x\right)$ is the long distance bill, and $x$ is the number of minutes spoken.

Last month, his long distance bill was $18.64#. Let's replace $f \left(x\right)$with $18.64$: $R i g h t a r r o w 18.64 = 0.08 x + 6$If we solve for $x$, we will find the number of minutes for which Carlos was billed: $R i g h t a r r o w 12.64 = 0.08 x$$R i g h t a r r o w 158 = x$$\therefore x = 158$Therefore, Carlos was billed for $158\$ minutes.