Question

Luana bought a new phone and plan. She paid $175. after three months, She paid $295. after 6 months. Write an equation that models her cost, C, after m months.

Answer 1

Answer: Hence, our required model will be

$C=40m+55$

Explanation:

Since we have given that

Luana bought a new phone and

For 3 months, the amount she paid = $175

For 6 months, the amount she paid = $295

Now, we have to model an equation ,

Here, let cost be 'C' and

Let number of months be 'm'.

So, we will use the "equation of line" i.e. for two point slope form :

Here y represented by 'C' and x represented by 'm'

So,

$C-C_0=\frac{295-175}{6-3}(m-m_0)\\\\C-175=\frac{120}{3}(m-3)\\\\C-175=40(m-3)\\\\C-175=40m-120\\\\C=40m-120+175\\\\C=40m+55$

Hence, our required model will be

$C=40m+55$