All categories

3 years ago

HELP!!!

Mathematics

1 answer:

scoundrel [369]3 years ago

3 0

Answer:

The metalworker should use 60 kg of metal alloy that is 70% copper and 40 kg of metal alloy that is 20% copper.

Step-by-step explanation:

System of Equations

Let's call

x=amount of metal alloy that is 20% copper

y=amount of metal alloy that is 70% copper

The metalworker wants to create 100 Kg of 50% copper alloy. This gives us the first relation

x+y=100

The combination of 20% of x and 70% of y will produce 50% of the sum of both, thus

20x+70y=50(x+y)

Operating

20x+70y=50x+50y

Reducing and dividing by 10

2y=3x

The system of equations is easily solved by isolating x in the first equation

x=100-y

And replacing into the last equation

2y=3(100-y)

Operating

2y=300-3y

5y=300

y=60

Thus

x=100-60=40

The metalworker should use 60 kg of metal alloy that is 70% copper and 40 kg of metal alloy that is 20% copper.

You might be interested in

The human body has a normal temperature of 98.6°F. Doctors will get worried if a sick patient has a temperature that varies from

makvit [3.9K]

Answer:

$|T- 98.6| \geq 3$

And in order to solve this we have two possibilities:

Solution 1

$T -98.6 \leq -3$

And solving for T we got:

$T \leq 98.6- 3$

$T\leq 95.6$

Solution 2

And the other options would be:

$T -98.6 \geq 3$

$T \geq 101.6$

Step-by-step explanation:

For this case we can define the variable os interest T as the real temperature and we know that if we are 3 F more than the value of 98.6 we will be unhealthy so we can set up the following equation:

$|T- 98.6| \geq 3$

And in order to solve this we have two possibilities:

Solution 1

$T -98.6 \leq -3$

And solving for T we got:

$T \leq 98.6- 3$

$T\leq 95.6$

Solution 2

And the other options would be:

$T -98.6 \geq 3$

$T \geq 101.6$

6 0

3 years ago

How much will it cost to pour a circular slab 18 ft in diameter by 3 in. For a patio if the concrete costs $40.00 per cubic yard

sasho [114]

A circular concrete slab is a cylinder. Vol = pi%2Ar%5E2%2Ah
in this cylinder:
r = 18%2F2 = 9 ft
h = 3%2F12 = .25 ft
:

Find the volume in cu/ft:
V = pi%2A9%5E2%2A.25
V = 63.61725 cu/ft
:
Change to cubic yds; (1 cu/yd = 27 cu/ft) and multiply by $40:
Cost = 63.61725%2F27 * 40
Cost = $94.25

In practical terms , they may require you to buy 3 cu/yds , which is $120

Yan na po

4 0

3 years ago

Please help this is algebra 1 problem is in the picture

Naddika [18.5K]

Answer:

0,1,2,3,4,5

Step-by-step explanation:

You can not buy more than 5 books because you'd have a negative amount of money. So 0,1,2,3,4,5 are the possible values for b.

7 0

3 years ago

How do you do 5+5?

steposvetlana [31]

Answer:

If you had 5 apples and Johnny gave you five more how much do you have? Lets count

10 OMG 5+5 is 10

6 0

3 years ago

Giving brainiliest answer!!

Ivan

Answer:

Step-by-step explanation:

1/16

2^-2 * 2^-2

2^2 * 2^-6

1/4^-2

4 0

3 years ago