Question

Alison set aside $55 each month to spend on books and cd .If she spends c dollar on cds given a month she may spend b dollar on book where c +b =55. Graph the equation and use the graph to estimate the amount Alison may spend on books in March if she spends 30 on CDs

Answer 1

For this case we have the following equation:
c + b = 55
Where,
c: number of CDs
b: number of books
For c = 30 we have:
30 + b = 55
From here, we clear the value of b.
We have then:
b = 55-30
b = 25
Note: observe in the graph that when the value of c is 30, the value of b is 25.
Answer:
the amount Alison may spend on books in March if she spends 30 on CDs is:
b = 25
See attached image.