suppose you bought some 32 cent stamps and some 20 cent stamps. you spent $3.92 for 16 stamps. how many of each stamp did you buy?
x = number of 32 cent stamps
y = number of 20 cent stamps
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x+y = 16
0.32x + 0.20y = 3.92
solve for x and y.
Check my thinking.
x + 20y = 12.25
i don't understand how to get the numbers for x and y
help please
6 32 cent stamps
10 20 cent stamps
Sure, I'd be happy to help you understand how to solve for x and y in this problem!
To find the values of x and y, we need to solve the system of equations you have provided:
1. x + y = 16
2. 0.32x + 0.20y = 3.92
We can use either substitution or elimination method to solve this system. Let's use the elimination method in this case.
First, let's multiply the first equation by 0.20 to make the coefficients of y in both equations the same:
0.20(x + y) = 0.20(16)
0.20x + 0.20y = 3.20
Now, let's subtract this equation from the second equation:
0.32x + 0.20y - (0.20x + 0.20y) = 3.92 - 3.20
0.32x - 0.20x = 0.72
0.12x = 0.72
To solve for x, we can divide both sides of the equation by 0.12:
x = 0.72 / 0.12
x = 6
Now that we have x, we can substitute it back into either of the original equations to solve for y. Let's use the first equation:
6 + y = 16
y = 16 - 6
y = 10
So, you bought 6 of the 32 cent stamps and 10 of the 20 cent stamps.
To check if this is correct, we can substitute the values back into the second equation:
0.32(6) + 0.20(10) = 3.92
1.92 + 2 = 3.92
3.92 = 3.92
Since the equation is true, our solution is correct.
I hope this explanation helps you understand the process of solving this type of problem! Let me know if you have any further questions.