Susan has $25. She is going to spend $4 on a book, then $3 per day on lunch. a) Write an equation that represents the following question: “How many days can Susan buy lunch with this plan?” b) Solve your equation, and check your solution.

3+2x <= 25

dang typo.

4+3x <= 25

a) To represent the question "How many days can Susan buy lunch with this plan?" as an equation, we need to consider the amount of money Susan has and the cost of each day's lunch.

Let x represent the number of days Susan can buy lunch with her remaining money.

The cost of the book is $4, and the cost of lunch per day is $3. Since Susan has $25 initially, she spends $4 on a book, which leaves her with $25 - $4 = $21.

Then, for each day, she spends $3 on lunch. So, the amount of money Susan has after a certain number of days can be calculated using the equation:

Amount of money after x days = Initial amount - Cost of the book - (Cost of lunch per day * number of days)

This equation can be written as:

$21 - $3x = 0

b) To solve the equation $21 - $3x = 0, we need to isolate the variable x.

Starting with the given equation:

$21 - $3x = 0

We can subtract $21 from both sides of the equation:

$21 - $21 - $3x = 0 - $21

This simplifies to:

$0 - $3x = -$21

Next, dividing both sides of the equation by -$3:

($0 - $3x) / -$3 = -$21 / -$3

This further simplifies to:

(-$3x) / -$3 = -$21 / -$3

x = 7

So, Susan can buy lunch for 7 days with this plan.

To check our solution, we can substitute the value of x (7) back into the equation we originally wrote:

$21 - $3(7) = 0

This simplifies to:

$21 - $21 = 0

And indeed, this equation is true. Therefore, our solution is correct. Susan can buy lunch for 7 days with this plan.