Answer:
c
Step-by-step explanation:
The answer is 9.77 hope this helps
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
(n-21)/2=4n is the equation
First, divide what is in the parentheses by 2
0.5n-10.5=4n
Then, multiply the whole equation by 2 so we have all whole numbers
n-21=8n
Move N so that it is with 8n
7n=-21
Divide 21 by 7
n=-3
Solution: The number (n) is equal to -3