P E M D A S
Parentheses first:
So, 12 + 4 x 13 - 2
12 + 52 - 2
64 - 2
62
V = 297 for a square pyramid, I hope its right..
x and y are the packs of organic and inorganic fertilizer, respectively.
pounds of nitrogen added = 2x + 6y = 120
pounds of potassium added = 3x + 2y = 54
eliminate the y terms. subtract the first equation from 3 times the second equation.
9x + 6y = 162
-2x - 6y = -120
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7x = 42
x = 6
y = 18
