We have been given that a jeweler has 5 rings, each weighing 12 g, made of an alloy of 20% silver and 80% gold.
Upon melting all 5 rings, the weight of the material will be 12*5=60 grams.
We have been given that the alloy contains 20% silver and 80% gold. Further, let us assume that x grams of silver are added to the melted material so that it has 64% gold and 36% silver.
Therefore, we can set up an equation:

Therefore, we get an equation:


Therefore, 15 grams of silver must be added to the melted material in order to reduce the gold content to 64%.
Go to Desmos.com. It’ll graph it for you
Answer:
x = 25
Step-by-step explanation:
Since the triangles are congruent then corresponding angles are congruent.
That is ∠ D and ∠ B are corresponding angles and congruent, thus
4x - 20 = 2x + 30 ( subtract 2x from both sides )
2x - 20 = 30 ( add 20 to both sides )
2x = 50 ( divide both sides by 2 )
x = 25
Answer: 69
Step-by-step explanation: The hypotenuse of the atom and it’s vastly large core equals the square root of 420 divides by 5.4 which equals 69.