Answer:
750 grams of 60% alloy
Step-by-step explanation:
Define x = amount of 60% alloy and y = amount of 20% alloy
Equating the amounts of gold:
0.6x+0.2y = 1000(0.5)
Since there must be 1000 grams total:
x+y = 1000
Writing the 2 resulting equations together:
0.6x + 0.2y = 500
x + y = 1000
Multiply the first equation by 5:
3x + y = 2500
x + y = 1000
Subtracting the 2nd equation from the 1st:
2x = 1500
x = 750
Answer: 750 grams of 60% alloy
Answer:


Step-by-step explanation:
A) If AB is a diameter, Then ACB is a 90 degrees angle because In a semi-circle (AB is a diameter which divides the circle into 2 equal parts), the angle opposite to the diameter is of 90 degrees.
So, <ACB = 90 degrees
Then <a = 180-90-28
=> <a = 62 degrees
B) The opposite interior angles of a quadrilateral inscribed in a circle add up to 180 degrees.
So,
=> <a + <b = 180
=> <b = 180-62
=> <b = 118 degrees
Answer:
<h2>270 ft²</h2>
Step-by-step explanation:
<h3>METHOD 1:</h3>
<em>Look at the picture</em>
We can divide a given polygon into three rectangles:

The formula of an area of a rectangle <em>l × w </em>:

Calculate the area of each of the rectangles:

The area of the given polygon:

<h3 /><h3>METHOD 2:</h3>
<em>Look at the second picture</em>.
We subtract the field of the smaller rectangle (<em>11ft × 6ft</em>) from the field of the large rectangle (<em>21ft × 16ft</em>):

9514 1404 393
Answer:
divide by x
Step-by-step explanation:
To answer your question, you can get from A to B by dividing by x:

However, this is only a valid operation if x ≠ 0. In this equation, x = 0, so that division is not valid.
__
A better approach to the solution is to put the equation in standard form:
f(x) = 0
You can get there by subtracting 3x from both sides.
5x -3x = 3x -3x
2x = 0
Now, you can legitimately divide by 2 to find ...
x = 0 . . . . . . . . the reason why dividing by x is not allowed