Pleaseeee help :) and don’t answer unless you really know the answer please

Describe and correct the error(s) made in each of the problems below.

ladessa [460]

Answer:

$\displaystyle \frac{1-x}{(5-x)(-x)} =-\frac{x-1 }{ x(x-5)}$

$\displaystyle \frac{5}{s}\times \frac{2}{5} =\frac{2}{s}$

Step-by-step explanation:

Errors in Algebraic Operations

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

$1-x / (5-x)(-x)=x-1 / x(x-5)$

Let's arrange into format:

$\displaystyle \frac{1-x}{(5-x)(-x)} =\frac{x-1 }{ x(x-5)}$

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

$\displaystyle \frac{1-x}{(5-x)(-x)} =-\frac{x-1 }{ x(x-5)}$

Now for the second expression

$5/s+2/5=2/s$

Let's arrange into format

$\displaystyle \frac{5}{s}+\frac{2}{5} =\frac{2}{s}$

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

$\displaystyle \frac{5}{s}\times \frac{2}{5} =\frac{2}{s}$

6 0

2 years ago

Please answer this question

Y_Kistochka [10]

$\bold{\huge{\underline{ Solution }}}$

Before answering the given question, you should know the difference between polygon and regular polygon. 

Polygon :- It is closed figure constitute of straight line having different measurements and also having varies angles.
Regular polygon :- It is also a closed figure constitute of straight lines which having equal measuresment and all the angles of the given polygon are equal .

There are different types of polygon based on the sides :-

A polygon having 3 sided called triangle ,having 4 sides called quadrilateral ,having 5 sides pentagon and so on.

<h3>Let's Begin :-</h3>

I have thought to make a 4 side polygon that is quadrilateral.

Steps of construction :-

Step - 1 :- Draw a 5 cm line AB horizontally
Step - 2 :- Then , From a point B, Draw a Vertical line of 5 cm and named it BC
Step - 3 :- Then, From a point C, Draw a horizontal line of 5 cm and named it CD
Step - 4 :- Now, join the line AD
Step - 5 :- Measure all the angles form by the 4 sides of the quadrilateral.