Question

Име­ет­ся два спла­ва. Пер­вый сплав со­дер­жит 5% ни­ке­ля, вто­рой — 30% ни­ке­ля. Из этих двух спла­вов по­лу­чи­ли тре­тий сплав мас­сой 100 кг, со­дер­жа­щий 20% ни­ке­ля. На сколь­ко ки­ло­грам­мов масса пер­во­го спла­ва мень­ше массы вто­ро­го?

Answer 1

X - 1 сплав y - 2 сплав
Составим систему
x+y=100
0.05*x+0.3*y=0.2*100  домножим второе уравнение на -20 и сложим оба уравнения 
 x+y=100
-x-6y=-400
-5y=-300
y=60  тогда x=40
Jndtn 60-40=20

Answer 2

Problem Analysis

We are given two alloys: one containing 5% nickel and the other containing 30% nickel. From these two alloys, a third alloy is obtained with a mass of 100 kg and containing 20% nickel. We need to determine the mass of the first alloy in relation to the mass of the second alloy.

Solution

Let's assume the mass of the first alloy is x kg. Since the mass of the third alloy is 100 kg, the mass of the second alloy can be calculated as (100 - x) kg.

The nickel content in the first alloy is 5% of x kg, which is 0.05x kg. The nickel content in the second alloy is 30% of (100 - x) kg, which is 0.3(100 - x) kg. The nickel content in the third alloy is 20% of 100 kg, which is 0.2 * 100 kg.

According to the problem, the nickel content in the third alloy is the sum of the nickel contents in the first and second alloys. Therefore, we can set up the following equation:

0.05x + 0.3(100 - x) = 0.2 * 100

Now, let's solve this equation to find the value of x, which represents the mass of the first alloy.

0.05x + 0.3(100 - x) = 0.2 * 100 0.05x + 30 - 0.3x = 20 -0.25x = -10 x = -10 / -0.25 x = 40

Therefore, the mass of the first alloy is 40 kg. The mass of the second alloy is (100 - 40) kg, which is 60 kg.

Answer

The mass of the first alloy is 40 kg, which is less than the mass of the second alloy, which is 60 kg.