Answer:
14 bags of snacks.
Explanation:
x = the first number 
y = the second number 
x minus y = 3 
x plus y = 13 
x - y = 3 
x + y = 13 
 
3 x = 8 x + y = 13 8 + y = 13 y = 5 x - y = 3 x +y = 13 2x = 16   
The first number = 8 
The second number = 5 
2x = 16 
Difference of the numbers is 3 
x = 8 
 
8 – 5 = 3 
Sum of the numbers is 13 
x + y = 13 
 
8 + 5 = 13 
8 + y = 13 
y = 5 
 
4 snacks plus beverages = 371 beverages = snacks plus 19 
The 8th grade class supplied bags of snacks and beverages for the school dance. They supplied 19 more beverages than bags of snacks. The dance was supplied with a total of 371 items. 
x = the number of snacks 
y = the number of beverages 
snacks plus beverages = 371 
beverages = snacks plus 19 
x + y = 371 
y = x + 19 
 
5 x + y = 371 
y = x + 19 
Number of snacks = 176 
Number of beverages = 195 
x + x + 19 = 371 
2x = 371 
total number of snacks = 371 
2x = 352 
= 371? 
 
371 = 371 
x = 176 
19 more beverages than snacks 
y = x + 19 
= 195 
y = 
 
195 = 195 
y = 195 
 
 
6 The seventh and eighth grade bands held a joint concert 
The seventh and eighth grade bands held a joint concert. Together there were 188 band members. If the eighth grade band is 3 times as big as the seventh grade band, how big is the eighth grade band? 
x = size of the 7th grade band 
y = size of 8th grade band 
7th grade and 8th grade together = 188 8th grade is 3 x 7th grade 
x + y = 188 
y = 3x 
 
7 x + 3x = 188 x = 47 y = 3(47) y = 141 x + y = 188 y = 3x 4x = 188  
7th grade band = 47 students 
8th grade band = 141 students 
x + 3x = 188 
4x = 188 
7th and 8th grade together = 188 
= 188? 
x = 47 
 
188 = 188 
y = 3x 
8th grade is 3 times as big as 7th grade 
y = 3(47) 
141 = 3(47) 
 
141 = 141 
y = 141 
 
8 x + y = 81 x = 2y earrings plus necklaces = 81 
Amy has 81 pieces of jewelry. She has twice as many earrings as she has necklaces 
x = number of earrings 
y = number of necklaces 
earrings plus necklaces = 81 
earrings = 2 x necklaces 
x + y = 81 
x = 2y 
 
9 2y + y = 81 y = 27 x = 2(27) x = 54 x + y = 81 x = 2y 3y = 81  x = 2y 
Number of earrings = 54 
Number of necklaces = 27 
2y + y = 81 
3y = 81 
81 pieces of jewelry total 
= 81? 
y = 27 
 
81 = 81 
x = 2y 
Twice as many earrings as necklaces 
x = 2(27) 
2(27) = 54 
 
54 = 54 
x = 54 
 
10 9x + 6y = 48 6x + 12y = 72 9 rose plus 6 lily = 48 
Julia is making candles. In the morning, she made 9 rose candle plates and 6 lily candle plates. They had a total of 48 candles. In evening, she made 6 rose candle plates and 12 lily candle plates. They had a total of 72 candles. How many candles did each plate have? 
x = candles on rose plates 
y = candles on lily plates 
9 rose plus 6 lily = 48 
6 rose plus 12 lilly = 72 
9x + 6y = 48 
6x + 12y = 72 
 
11 x = 2 6(2) + 12y = 72 12y = 60 y = 5 [9x + 6y = 48] (-2) 6x + 12y = 72 
Candles on the rose plates = 2 
Candles on the lilly plates = 5 
-18x - 12y = -96 
6x +12y = 72 
9 rose and 6 lilly is 48 plates 
9(2) + 6(5) = 48 
-12x = -24 
 
= 48 
x = 2 
6 rose and 12 lilly is 72 plates 
6(2) + 12y = 72 
6(2) + 12(5) = 72? 
y = 72 
 
= 72 
12y = 60 
y = 5 
 
 
12 3 adults plus 12 children = 162 3 adults plus 8 children = 122 
The cost of admission to a popular music concert was $162 for 12 children and 3 adults. Admission for another group was $122 for 8 children and 3 adults. How much was the admission for each child and adult? 
x = the cost of one adult ticket 
y = the cost of one child ticket 
3 adults plus 12 children = 162 
3 adults plus 8 children = 122 
3x + 12y = 162 
3x + 8y = 122 
 
13 3x + 12y = 162 
[3x + 8y = 122] (-1) 
The cost of one adult ticket = $14 
The cost of one child ticket = $10 
3x + 12y = 162 
-3x + -8y = -122 
12 children and 3 adults spent $162 
12 at $10 and 3 at $14 = $162? 
4y = 40 
 
$120 + $42 = $162 
y = 10 
8 children and 3 adults spent $122 
3x + 12(10) = 162 
8 at $10 and 3 at $14 = $122? 
3x = 162 
 
$80 + $42 = $122 
3x = 42 
x = 14