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 consider the change in gold content and the percentage increase in gold after adding 50g of gold to the original alloy.

Let's assume the initial amount of silver in the alloy is x grams.

According to the given information, the original alloy contained 40g of gold. After adding 50g of gold, the gold content increased by 20%. This means the new alloy contains 40g + 20% of 40g = 40g + 8g = 48g of gold.

Since the total weight of the alloy remains the same (40g + x), we can set up the following equation:

40g + x = 48g + x

Simplifying the equation, we find that the amount of silver in the alloy is 48g.

Therefore, the amount of silver in the alloy is 48g.