So,
To find the percentage that the copper comprises, just divide the amount of copper by the total amount of metal in the coin. In this case, we will change the denominator so that it is 100, which can easily be converted into a percentage, which is really just a fraction out of 100.

75%
75% of the metal in the coin is copper.
Answer:
-30bc + 50bd
Step-by-step explanation:
3a + 5b/3c - 5d = 3a - 5b/3c - 5d
(3c - 5d)(3a - 5b) = (3a + 5b)(3c - 5d)
9ca - 15bc - 15da + 25db = 9ac - 15ad + 15bc - 25bd
9ca -15bc - 15da + 25db - 9ac + 15ad - 15bc + 25bd
9ca and -9ac and -15da and 15ad cancel each other out, so
-30bc + 50db is left
Answer:
maybe 20
Step-by-step explanation:
or find it out yourself
Hi! your answer should be 7.64 if I am not mistaken