Hello! I have two math questions:

1.) Marcos has 28 coins that are all nickels (n) and dimes (d). The value of the coins is $2.05. Which system of equations can be used to find the number of nickels and the number the dimes?

A. n + d = 28
5n + 10d = 205


B. n + d = 28
10n + 5d = 2.05


C. n + d = 205
n + d = 28


D. 10n + 5d = 205
n + d = 28

2.) Two groups of students order burritos and tacos at a local restaurant. One order of 3 burritos and 4 tacos costs $11.33. The other order of 9 burritos and 5 tacos costs $23.56. Which system of equations represents this problem situation?



A. x + y = 7
x + y = 14


B. 3x + 4y = 11.33
9x + 5y = 23.56


C. 3x + 4y = 23.56
9x + 5y = 11.33


D. x + y = 12
x + y = 9

#1 should be obvious

since d is "dime", it has to be multiplied by 10 (10 cents in a dime)
and n is "nickels" it has to be multiplied by 5
So what do you think?

#2, Once you define what x and y represent, the answer should be obvious as well.
I would have used b and t instead of x and y.

So

#1 is A and #2 is D?

correct for #1, wrong for #2

#2
If x is cost of buritos, y is cost of tacos
"3 burritos and 4 tacos costs $11.33" --->3x+4y = 11.33

"9 burritos and 5 tacos costs $23.56" ----> 9x + 5y = 23.56

B !!!!

Now , how easy was that? Notice how I just translated the "math" into English ?

For the first question:

To find the number of nickels and the number of dimes, we can set up a system of equations based on the given information.

Let's use variables n for the number of nickels and d for the number of dimes.

Since Marcos has a total of 28 coins, the first equation is n + d = 28.

The value of the coins is $2.05. We know that nickels are worth 5 cents and dimes are worth 10 cents, so we can set up the second equation as 5n + 10d = 205 (converting dollars to cents).

Now we need to determine which system of equations matches the given information:

A. n + d = 28
5n + 10d = 205

B. n + d = 28
10n + 5d = 2.05

C. n + d = 205
n + d = 28

D. 10n + 5d = 205
n + d = 28

The correct answer is option A, because it correctly represents the relationships between the number of coins and their values.

Moving on to the second question:

Similar to the first question, we need to set up a system of equations to represent the problem.

Let's use variables x for the number of burritos and y for the number of tacos.

According to the given information, the first order of 3 burritos and 4 tacos costs $11.33. This can be expressed as the equation 3x + 4y = 11.33.

The second order of 9 burritos and 5 tacos costs $23.56, which can be written as the equation 9x + 5y = 23.56.

Now we need to determine which system of equations matches the given information:

A. x + y = 7
x + y = 14

B. 3x + 4y = 11.33
9x + 5y = 23.56

C. 3x + 4y = 23.56
9x + 5y = 11.33

D. x + y = 12
x + y = 9

The correct answer is option B, because it correctly represents the cost of the two orders in terms of the number of burritos and tacos.