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
You have to keep order of operations in mind.
1. Take care of the parentheses; distribute.
-3+6x-3=-20-8x
Simplified: 6x-6=-20-8x
2. Isolate the x variable.
Add 8x to both sides and add 6 to both sides.
14x=-14
3. Solve for x.
Divide by 14 on both sides.
x=-1
To find the length and width of 3 different rectangles that have an area of 48 square inches, you can use the factor pairs that result in 48.
The reason is that to find the area of a rectangle you multiply two dimensions.
2 in x 12 in
3 in x 8 in
4 in x 6 in
On all these either one could be the length and the other the width.
Question: 2x - 4 + 5x
Simplified: 7x - 4
I would pick C sorry if it’s wrong
