George and Paul use a metal alloy that is 18.1% copper to make jewelry. How many ounces of an alloy that is 14% copper must be mixed with an alloy that is 23% copper to form 90 ounces of the desired alloy?

Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.

Step-by-step explanation:

Each ounce of the 14% copper contains 0.14 ounce of pure copper.

Each ounce of the 23% copper contains 0.23 ounce of pure copper.

Each ounce of the 18.1% copper contains 0.181 ounce of pure copper.

Use x ounces of the 14% and y ounces of the 23% to make 90 ounces of 18.1% alloy.

x+y  = 90

y = 90-x

0.14x + 0.23y = 0.181·90

0.14x + 0.23(90-x) = 16.29

0.14x + 20.7 - 0.23x = 16.29

-0.09x + 20.7 = 16.29

4.41 = 0.09x

x = 49

y = 90-x = 41

Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.

4 puzzles in 3 hours

step-by-step explanation:

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

⇒

also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt