Question

The cost of a ticket to an amusement park was increased by 4 dollars. The new cost is twenty-eight dollars.

a. Write a one-step equation that could be solved to find the old price. Let p represent the old price.
b. Solve the equation you wrote in Part a. Show all your work.
c. Explain how you know that the solution you found in Part b is the correct answer.

Answer 1

If p is the old price, and the new price is $4 more, how would you write that?

Answer 2

idk

Answer 3

@mathstudent55

Answer 4

Let me ask you this way.
Let p represent a number.
How do you write 4 more than p, or 4 added to p?

Answer 5

by adding to both sides?

Answer 6

There are no sides here. We don't have an equation yet. An equation will come soon.

Think of the number 20.
Without doing the addition, how do you write 4 more than 20, or 4 added to 20?
Don't add 20 and 4, just show the addition.

Answer 7

ok

Answer 8

In this last question, what I was looking for was
20 + 4
That shows the addition of 20 and 4, or 4 more than 20.

In your problem above, it's similar. You have a number represented by the variable p.
You need to represent 4 more than p.
You do that by writing
p + 4
The old price is p. The new price is 4 more than p, so it's p + 4.

Now we get to the equation.
We are told the new price is $28.
Since we know the new price is p + 4, and the new price is also $28, that means p+4 must be the same a 28.
Now we write an equation:

p + 4 = 28

Answer 9

ight

Answer 10

now i add 4 to both sides

Answer 11

?

Answer 12

This is the answer to part a. p + 4 = 28

Answer 13

In part b. you need to solve the equation.

Answer 14

p is 24

Answer 15

@m

Answer 16

Correct. The way to solve the equation is that since you have p + 4 on the left side and you want p alone, you must get rid of the plus 4. The way you get rid of an addition is by doing the opposite operation which is subtraction.
p + 4 - 4 = p
In an equation, you must do the same operation to both sides, so you must subtract 4 from both sides.
p + 4 - 4 = 28 - 4
p = 24
That is the solution to part b.

Answer 17

ok so wats c.

Answer 18

Now for part c. you must explain why you know the solution p = 24 is correct.
Since the problem stated the old price plus 4 is 28, we can try it with 24 to see if it works.
Is 24 + 4 equal to 28?
The answer is yes, 24 + 4 equals 28, so our solution is correct.
Not only that, the only number there is that when 4 is added to it will give you 28 is 24. There is no other number that can be the solution.

Answer 19

ight thx 4 ur help

Answer 20

you're wlcm