Answer:
x=280
Step-by-step explanation:
We have, 15% × x = 42
or,
15
100
× x = 42
Multiplying both sides by 100 and dividing both sides by 15,
we have x = 42 ×
100
15
x = 280
If you are using a calculator, simply enter 42×100÷15, which will give you the answer.
Answer:
Step-by-step explanation: put your fraction 6 over 15
Check the picture attached.
Let OB be the radius of circle with center O.
Let B' be the image of B after the described rotation
OB and OB' are sides of the equilateral triangle OBB'.
The x coordinate of B' is the midpoint of OB, that is 5.
In the right triangle B', point (5, 0) and B:
Distance point (5, 0) to B is 5
|B'B|=|OB|=10
so by the pythagorean theorem:

units
Answer:
where is the figures to solve.
Answer:


Step-by-step explanation:
<u>Errors in Algebraic Operations
</u>
It's usual that students make mistakes when misunderstanding the application of algebra's basic rules. Here we have two of them
- When we change the signs of all the terms of a polynomial, the expression must be preceded by a negative sign
- When multiplying negative and positive quantities, if the number of negatives is odd, the result is negative. If the number of negatives is even, the result is positive.
- Not to confuse product of fractions with the sum of fractions. Rules are quite different
The first expression is

Let's arrange into format:

We can clearly see in all of the factors in the expression the signs were changed correctly, but the result should have been preceeded with a negative sign, because it makes 3 (odd number) negatives, resulting in a negative expression. The correct form is

Now for the second expression

Let's arrange into format

It's a clear mistake because it was asssumed a product of fractions instead of a SUM of fractions. If the result was correct, then the expression should have been
