The total number of gifts = x+y.
The inequality is:

Key chains cost $1, Magnets $0.50
Total Cost = x + 0.5y
Inequality is:

Without graphing you can solve system by using substitution:

This is one solution where the maximum x value is given.
So the most keychains that can be purchased is 16. However, because magnets are cheaper, more can be purchased as long as cost remains under 20.
If you solve both inequalities for "y", you get the upper and lower bounds for how many magnets can be purchased given a quantity of keychains.

This is complete solution which gives all possible combinations.
(Graph is Attached)
first step is to subtract 21 from both sides
2m+21-21=3-21
2m=-18
2m/2 and -18/2
m=-9
So the final answer is m=-9 (negative nine equals m)
Answer:
A = 14.2/1.1 hours
B = 5.091 hours
Step-by-step explanation:
Formulate 2 simultaneous equations
5.7A + 6.8B = 111.40..........(1)
A +B =18...............................(2)
Multiply each item in (2) by 5.7 to get
5.7A + 5.7B = 97.2............(3)
subtract (1) - (3) on each side
5.7A -5.7A + 6.8B - 5.7B = 111.40 -97.2
1.1B = 14.2
B = 14.2 /1.1
to get A use equation (2)
A = 18 - B
A = 18 - 14.2/1.1 = 5.091
Since the triangles are similar, then 32 = x+7 those two angles are too
solve for "x"
now using proportions

solve for JK

solve for KG
the scale factor of the perimeter of both triangles is just the same as the ratio of the sides, or
The number 12 is missing in the data set.
<u>Step-by-step explanation</u>:
- The numbers are 9,12,16,18,23.
- The missing number is assumed to be 'x'
Mean = Sum of the integers / Total number of integers.
15 = (9+12+16+18+23+x) / 6
15 = (78+x) / 6
90 = 78+x
x = 90-78
x = 12