<span>A relation is a set of inputs and outputs, often written as ordered pairs (input, output). </span>
Let t be the number of triggerfish and p be the number of parrotfish
t + p = 320
t = 7p
7p + p = 320
8p = 320
p = 40
There are 40 parrotfish.
p = 40
t = 7(40)
t = 280
There are 280 triggerfish.
Check:
t + p = 320
280 + 40 = 320
320 = 320
We know the amount of copper is 85%, that means the rest is tin in the Alloy, so the tin is 15% of the Alloy then.
now, say "x" lbs is the total amount of the Alloy, and we know that 1 and 13/32 which is tin, is the 15% of "x", what the dickens is "x"?