1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jok3333 [9.3K]
2 years ago
12

A metalworker has a metal alloy that is 20​% copper and another alloy that is 70​% copper. How many kilograms of each alloy shou

ld the metalworker combine to create 90 kg of a 50​% copper​ alloy?
Mathematics
1 answer:
Amiraneli [1.4K]2 years ago
3 0
Answer: combine 36 kg 20% copper alloy and 54 kg 70% copper alloy.

Explanation

Construct your system of equations:

1) Variables:

x = kg of alloy with 20% copper content
y = kg of alloy with 70% copper content

2) First equation:

90 kg of alloy => 90  = x + y

3) Second equation:

90 kg 50% copper = 90 kg * 0.5 = 45 kg copper

x kg 20% copper = 0.2x

y kg 70% copper = 0.7y

=> 45 = 0.2x + 0.7y

4) System

x + y = 90
0.2x + 0.7y = 45

Solve the system

5) Mutiply the first equation times 0.2:

0.2x + 0.2y = 18

6) Subtract from the second equation:

0.2x - 0.2x + 0.7y - 0.2y = 45 - 18

0.5y = 27

y = 27 / 0.5 = 54

7) Replace into the first equation fo find x:

x = 90 - 54 = 36

Answer: 36 kg 20% copper alloy and 54 kg 70% copper alloy.

You might be interested in
The diagram shows a circle inside a square.<br> a<br> 16 cm<br> Work out the area of the circle.
Aliun [14]

Answer:

Side of square=Diameter of circle=16

Radius= Diameter/2=16/2=8

Area of circle=4Πr²

=4*3.14*8²

=803.84cm²

3 0
2 years ago
Eli has 7 games on his phone . his sister has 6 more than him which ratio compares the number of games on Eli's phone to the num
Assoli18 [71]

Answer:

7:13

Step-by-step explanation:

3 0
2 years ago
Read 2 more answers
Complete the statement using &lt; &gt;, or =. <br> |-18| __ 19<br> A: &lt;<br> B: &gt;<br> C: =
eduard

Answer:

<

Step-by-step explanation:

the inverse of -18 is +18. +18 is less than 19

4 0
2 years ago
In isosceles △ABC, points D and F are on leg CB while point E is on leg AB so that AC = AD = DE = EF = BF. Find the measures of
Solnce55 [7]

Answer:

Abs 12 -- ef de Venta de casas en Venta por que es UN hombre de casas abs

3 0
2 years ago
Read 2 more answers
Why would "-7" in the expression (x^2+3)-(x-7) become positive?
ryzh [129]
You would use the distributive property with the negative. So the second x becomes negative, but since the 7 is already negative it becomes positive. Think of it as if you put the two dashes together you can make a plus sign.
5 0
3 years ago
Read 2 more answers
Other questions:
  • If the total cost of z apples is a ​cents, what is the general formula for the​ cost, in​ cents, of w ​apples?
    8·1 answer
  • Is 81 both a perfect square and a perfect cube?
    5·2 answers
  • Which expression is the exponential form of 19y?
    12·1 answer
  • Between which two integers does Between which two integers does √11 lie?
    5·2 answers
  • . On a week-day paper route, Jennifer delivers the following number of papers in one week. What is the median number of papers t
    13·1 answer
  • How to convert (x+6)(x-2) to standard form
    5·1 answer
  • 47% of citizens in a district voted in the last election. 21% of citizens in the district are under 18. Being younger than 18 an
    11·1 answer
  • The price of 4 donuts and 2 croissants is $10. The price of 2 donuts and 3 croissants is $9. How much does 1 donut and 1 croissa
    9·1 answer
  • Whats the solution pls help
    15·2 answers
  • PLZ HELP AS SOON AS POSSIBLE!!!!!!!!! WILL GIVE LIKE, 5 STARS, &amp; BRAINLIEST; THE WHOLE SHEBANG; (Worth 20 Points!)
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!