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
THIS IS THE COMPLETE QUESTION BELOW
The demand equation for a product is p=90000/400+3x where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50.
Answer
$168.27
Step by step Explanation
Given p=90000/400+3x
With the limits of 40 to 50
Then we need the integral in the form below to find the average price
1/(g-d)∫ⁿₐf(x)dx
Where n= 40 and a= 50, then if we substitute p and the limits then we integrate
1/(50-40)∫⁵⁰₄₀(90000/400+3x)
1/10∫⁵⁰₄₀(90000/400+3x)
If we perform some factorization we have
90000/(10)(3)∫3dx/(400+3x)
3000[ln400+3x]₄₀⁵⁰
Then let substitute the upper and lower limits we have
3000[ln400+3(50)]-ln[400+3(40]
30000[ln550-ln520]
3000[6.3099×6.254]
3000[0.056]
=168.27
the average price p on the interval 40 ≤ x ≤ 50 is
=$168.27
Answer:
16/45
Step-by-step explanation:
Step 1: When dividing fractions, use “KFC”. It means Keep the first fraction, Flip the second one, and
Change it to multiplication
-4/20 ÷ -9/16 → -4/20 ∙ 16/-9
Step 2: Reduce any fractions if necessary, it makes multiplying them easier and you will have to reduce anyway at the end. It’s easier arithmetic to reduce at this step. The first fraction reduces because both the numerator and denominator are divisible by 4.
-1/5 ∙ 16/-9
Step 3: Multiply numerators and denominators together to get one fraction
(-16)/(-45)
Step 4: Cancel out the negatives, a negative divided by a negative is a positive. Our final answer is
16/45
Answer:
28
Step-by-step explanation:
Using the rule of radicals
× 
⇔ 
= 
= 
×
= 4
Then
7
= 7 × 4
= 28
