X - number of 5 c stamps,
y - number of 15 c stamps,
z - number of 25 c stamps.
The system:
x + y + z = 160
y = 3 x
0.05 x + 0.15 y + 0.25 z = 25 / * 100
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x + y + z = 160
y = 3 x
5 x + 15 y + 25 z = 2500 / : 5
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x + 3 x + z = 160
x + 3 y + 5 z = 500
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4 x + z = 160 / * ( - 1 )
10 x + 5 z = 500 / : 5
------------------------------
- 4 x - z = - 160
+
2 x + z = 100
-------------------------
- 2 x = - 160
x = 30, y = 90
z = 160 - 120 = 40
Answer:
- 30 of 5 c stamps,
- 90 of 15 c stamps,
- 40 of 25 c stamps.
Answer:
11 1/12
Step-by-step explanation:
6 1/3 = 19/3
7 1/4 = 29/4
2 1/2 = 5/2
19/3 + 29/4 - 5/2
We must find the LCM of 3, 4, and 2. This happens to be 12
3*4 = 12
4*3 = 12
2*6 = 12
Multiply each fraction by the factor that'll get it to 12.
19/3 * 4/4 = 76/12
29/4 * 3/3 = 87/12
5/2 * 6/6 = 30/12
Now go through the problem
76/12 + 87/12 - 30/12
76 + 87 = 163
163/12 - 30/12
163 - 30 = 133
133/12
Simplify
133/12 = 11.0833... or 11 1/12
Hope this helps.
9w^3 ...........................