# Math

posted by
**Nick** on
.

Answer this please!!!

Noelani was saving Luscious Lemon soda coupons, which came in the caps of the Luscious Lemon sodo bottles. There were two kinds of coupons: 5-point coupons and 2-point coupons. So far, she had collected 23 coupons, worth 76 points. How many 5-point and 2-point coupons did Noelani have?

Noelani was saving Luscious Lemon soda coupons, which came in the caps of the Luscious Lemon sodo bottles. There were two kinds of coupons: 5-point coupons and 2-point coupons. So far, she had collected 23 coupons, worth 76 points. How many 5-point and 2-point coupons did Noelani have?

** Let X = # of 5 pt coupons.
Y = # of 2 pt coupons.
We know X + Y = 23
and we know the total number of points which is 76.
5X + 2Y = 76
You have two unknowns and two equations. Solve for X and Y. Post your work if you run into trouble.
Ok we have two types of coupons Let f and t denote the number of five and two pointers respectively. Then
(1) f + t = 23
(2)5*f+2*t=76
From (1) f=23-t. Substitute that into (2) for for f to get
5*(23-t) + 2*t=76 or
5*23 -5t +2t = 76
Now solve for t, then solve for f using (1).
You could also have recognized this as a system of linear equation and added -5 times (1) to (2) and solved for t that way too. Either method will give the same result. For two variables, using the substitution way is usually the faster one to use.
14 5-point coupons and 8 2-point coupons so easy!!!!!!!!!!!
Fourteen 5-pt and eight 2-pt will not satisfy the equations . First, they add to 22 and not 23. The problem stated the total number of coupons was 23. Fourteen 5-pt will be worth 70. Eight 2-pt will be worth 16 and that adds to 76. However, BOTH equations must be satisfied so 14 and 8 are not correct.
12 5-pt 8 2-pt
12 + 8 is 20 and not 23. That doesn't work either. Solve the two equations to obtain the correct answer.
y=21-2x
If you have a question you should post it separately under "Post a New Question" at the top of this page. You should also explain what you want done with the equation y = 21-2x
10 5-point coupons and 13 2-point coupons.
Let X = # of 5 pt coupons.
Y = # of 2 pt coupons.
We know X + Y = 23
and we know the total number of points which is 76.
(5 x x=10) + (2 x y=13) = 76
50 + 26 = 76
i hve no idea
**