The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable
27, 140 is the correct answer
The total mass of the living things on the farm is 588 kg.
<h2><u>Mass calculation</u></h2>
Since on a farm there was a cow, 2 sheep and 3 chickens, to determine what is the total mass of the 1 cow, the 2 sheep, the 3 chickens, and the 1 farmer on the farm, the following calculation must be performed :
- (6.2 x 10) + (4 x 10 x 10) + (2 x 6 x 10) + (3 x 2 x 1) = X
- 62 + 400 + 120 + 6 = X
- 588 = X
Therefore, the total mass of the living things on the farm is 588 kg.
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592,722 is the correct answer
Answer:
20kg of 25% copper alloy
30kg of 60% copper alloy
Step-by-step explanation:
There are 2 kinds of metal, first metal(A) have 25% copper while the second metal(B) has 60% copper. The metalworker want to create 50kg of metal, which means the total weight of both metals is 50kg (A+B = 50). The metalworker also want the metal made of a 46% which is 23kg(0.25A + 0.6B = 0.46*50). From these sentences, we can derive 2 equations. We can solve this with substitution.
A+B = 50
A= 50-B
Let's put the first equation into the second.
0.25A + 0.6B = 0.46 *50
0.25(50-B) + 0.6B =23
12.5 - 0.25B + 0.6B =23
0.35B=23 -12.5
B= 10.5/ 0.35= 30
Then we can solve A
A= 50-B
A= 50-30
A=20
