Question

Сплав золота и серебра содержал 40г золота.После того как к нему добавили 50г золота,получили новый сплав,в котором содержание золота возросло на 20%.Сколько серебра было в сплаве?

Answer 1

Пусть х - кол-во серебра в граммах. Тогда из условия имеем уравнение:

90/(х+90) - 40/(х+40) = 0,2

90х + 3600 - 40х - 3600 = 0,2х² + 26х + 720

х² - 120х + 3600 = 0

(х - 60)² = 0

 х = 60 г

Ответ: 60 г.

Answer 2

Calculation of Silver Content in the Alloy

To calculate the amount of silver in the alloy, we need to determine the initial amount of silver and the change in the gold content after adding more gold.

Given information: - Initial gold content in the alloy: 40g - Additional gold added to the alloy: 50g - Increase in gold content after adding more gold: 20%

Let's calculate the initial silver content in the alloy:

1. Determine the initial total weight of the alloy: - Initial gold content: 40g - Initial silver content: Unknown (let's call it 'x') - Total weight of the alloy = Initial gold content + Initial silver content = 40g + x

2. Calculate the new total weight of the alloy after adding more gold: - Additional gold added: 50g - New total weight of the alloy = Initial total weight of the alloy + Additional gold added = (40g + x) + 50g = 90g + x

3. Calculate the new gold content in the alloy after the increase: - Increase in gold content: 20% - New gold content = Initial gold content + (Increase in gold content * Initial gold content) = 40g + (0.20 * 40g) = 40g + 8g = 48g

4. Set up an equation to solve for the initial silver content: - New gold content = Initial gold content + Additional gold added - 48g = 40g + x

5. Solve the equation for 'x' to find the initial silver content: - 48g - 40g = x - 8g = x

Therefore, the initial silver content in the alloy was 8g.

Please let me know if you need any further assistance!