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Darina [25.2K]
3 years ago
7

What is 75% pure gold.

Mathematics
2 answers:
pentagon [3]3 years ago
5 0

Answer:

Karats measure the parts per 24, so that 18 karat = ​18⁄24 = 75% and 24 karat gold is considered 100% gold.

Step-by-step explanation:

lutik1710 [3]3 years ago
4 0

Answer:

White Gold.

Step-by-step explanation:

This type of gold contains only 75% pure gold, not 100%.

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Not sure what to do here can someone please help
kumpel [21]

Answer:

  x = 2

Step-by-step explanation:

These equations are solved easily using a graphing calculator. The attachment shows the one solution is x=2.

__

<h3>Squaring</h3>

The usual way to solve these algebraically is to isolate radicals and square the equation until the radicals go away. Then solve the resulting polynomial. Here, that results in a quadratic with two solutions. One of those is extraneous, as is often the case when this solution method is used.

  \sqrt{x+2}+1=\sqrt{3x+3}\qquad\text{given}\\\\(x+2)+2\sqrt{x+2}+1=3x+3\qquad\text{square both sides}\\\\2\sqrt{x+2}=(3x+3)-(x+3)=2x\qquad\text{isolate the root term}\\\\x+2=x^2\qquad\text{divide by 2, square both sides}\\\\x^2-x-2=0\qquad\text{write in standard form}\\\\(x-2)(x+1)=0\qquad\text{factor}

The solutions to this equation are the values of x that make the factors zero: x=2 and x=-1. When we check these in the original equation, we find that x=-1 does not work. It is an extraneous solution.

  x = -1: √(-1+2) +1 = √(3(-1)+3)   ⇒   1+1 = 0 . . . . not true

  x = 2: √(2+2) +1 = √(3(2) +3)   ⇒   2 +1 = 3 . . . . true . . . x = 2 is the solution

__

<h3>Substitution</h3>

Another way to solve this is using substitution for one of the radicals. We choose ...

  u=\sqrt{x+2}\qquad\text{requires $u\ge0$}\\\\u^2-2=x\qquad\text{solve for x}\\\\u+1=\sqrt{3(u^2-2)+3}\qquad\text{substitute for x in the original equation}\\\\(u+1)^2=3u^2-3\qquad\text{square both sides, simplify a little}\\\\2u^2-2u-4=0\qquad\text{subtract $(u+1)^2$}\\\\2(u-2)(u+1)=0\qquad\text{factor}

Solutions to this equation are ...

  u = 2, u = -1 . . . . . . the above restriction on u mean u=-1 is not a solution

The value of x is ...

  x = u² -2 = 2² -2

  x = 2 . . . . the solution to the equation

_____

<em>Additional comment</em>

Using substitution may be a little more work, as you have to solve for x in terms of the substituted variable. It still requires two squarings: one to find the value of x in terms of u, and another to eliminate the remaining radical. The advantage seems to be that the extraneous solution is made more obvious by the restriction on the value of u.

6 0
2 years ago
In need of help pls. Try and answer asap.
Alina [70]

Answer:

Step-by-step explanation:

∠1 and 85 are supplementary

m∠1 = 180 - 85 = 95°

4 0
2 years ago
Whoever answer is the best gets brainlist
Otrada [13]
The answer is 18^8 because u add exponents

8 0
3 years ago
Read 2 more answers
a bowl of candies contains the following makeup of colors: 4 red, 2 yellow, 5 green, and 1 purple. taina is selecting a candy at
Ivanshal [37]

<u>Candies</u>

4 red

2 yellow

5 green

1 purple

- Taina doesn't like red candies.

4/4+2+5+1 = 4/12

4/12 is the probability Taina <em>will</em> get a red candy, but we're looking for the opposite.

12/12 - 4/12 = 8/12 = 2/3

The probability Taina will not select a red candy is 2/3.

8 0
3 years ago
Can someone help me with this question?
stiks02 [169]

5x−2(x+1)=14 ​

distribute

5x -2x-2 =14

3x-2 = 14

add 2 to each side

3x = 16

divide by 3

x=16/3

Answer x=16/3 or 5 1/3

7 0
3 years ago
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