Brass is made from a mixture of copper and other elements. a mixture that is 80% copper is combined with a mixture that is 60% copper, resulting in 100 pounds of brass that is 65% copper. which equation can be used to find x, the amount of 60% mixture used to create the 65% mixture?
a. 0.8(100 – x) + 0.6x = 100(0.65)
b. 0.6(100 – x) + 0.8x = 100(0.65)
c. 0.8(100) + 0.6x = 0.65(100 - x)
d. 0.6(x) + 0.8(100 + x) = 0.65

a.0.8(100 – x) + 0.6x = 100(0.65)

Step-by-step explanation:

The easiest way to find the answer is to derive the equation from the the data given.

The amount of 60% mixture is given as .

The amount of copper from 60% mixture =

The amount of copper from 80% mixture =

Therefore total amount of copper in 100 pound mixture is:

The amount of copper from 60% mixture + The amount of copper from 80% mixture

⇒

We can rearrange the equation as:

Percentage of copper in the final mixture can be derived by:

[Total pounds of copper/Total pounds of the mixture]×100

Percentage of copper in the final mixture is given as 65%

Therefore,

[Total pounds of copper/Total pounds of the mixture]×100=65%

=

This equation can be used to find the value of ..

Therefore the answer is a.0.8(100 – x) + 0.6x = 100(0.65)

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.

step-by-step explanation:

use context clues to figure out the meaning of the bolded word:  

the sage gardener knew when she had to water her plants.  

question 8 options:

mint plant

wise

happy

lazy