Kate paid a one time adoption fee when she got a puppy from her local animal shelter. Curious how much she had spent since she got the puppy (including the adoption fee), she decided to check after 3 months and again after 6 months. After 3 months the total amount she had spent was $176. After 6 months the total amount was $272. Write and graph a linear equation in slope-intercept form that represents the total cost y of adopting and caring for the puppy for x months.