Is these algebraic expression correct

  • Thread starter JakePearson
  • Start date
  • Tags
    Expression
The first line is x/3 - y/2 = -1, not x/3 - x/3 - y/2 + 4 = -1. In summary, for the first conversation, the correct solutions for x are -1 and -5. For the second conversation, the equations are set up correctly and the next step is to subtract x^2 - 7x - 8 from both sides. For the third conversation, there seems to be some confusion with the equations and the final answer for x should be -3/2 and y should be -10.
  • #1
JakePearson
52
0
1.(x - 3)2 = 4
x2 - 6x + 5 = 0
(x - 1)(x - 5) = 0
x = -1, -5
(is this correct)

2. 2x + 4 / x +1 = x - 8 / 2x - 1
(2x + 4)(2x - 1) = (x - 8)(x + 1
4x2 - 2x + 8x - 4 = x2 - 7x -8
4x2 - 6x - 4 = x2 - 7x - 8
(where do i go from here)

3. (x / 3) - (y / 2) = -1
(y / 2) = -4 - 3x
6x + y = -8
y = -8 - 6x
(x / 3) - (-4 - 3x) = -1
(10 / 3) x + 4 = -1
x = -5 / (10 / 3) = (-3 / 2) x = -3 / 2
6(-3 / 2) + y = -8
y = -8 + 6(-3 / 2)
y = -8 + (-18 / 2)
y = (-144 +- 16 / 16) y = -10
(is this correct)
 
Physics news on Phys.org
  • #2
1. No, they should be positive. If you plugged in either x=-1 or x=-5, you'd see that product didn't equal 0.

2. For this question, is what you're asking [tex]\frac{{2x + 4}}{{x + 1}} = \frac{{x - 8}}{{2x - 1}}[/tex]? If so, it looks good. Now you simply want to subtract [tex]x^2 - 7x - 8[/tex] from both sides so you have 0 on the right side and a simple quadratic on the left.

3. This looks a little confusing. Can you put spaces between each set of equations so we know exactly what you're doing? If the third line is suppose to be manipulation of the first line, it doesn't look correct.
 

1. Is it necessary to simplify algebraic expressions?

Yes, simplifying algebraic expressions is important because it helps to make the expression easier to understand and work with. It also helps to identify and cancel out any common factors, making the expression more efficient to solve.

2. How can I check if an algebraic expression is correct?

To check if an algebraic expression is correct, you can substitute values for the variables and simplify the expression. If the result is equivalent to the original expression, then it is correct.

3. What are the common mistakes to avoid when simplifying algebraic expressions?

Some common mistakes to avoid when simplifying algebraic expressions include:- Forgetting to apply the distributive property- Combining terms with different variables- Incorrectly applying exponent rules- Forgetting to simplify negative signs

4. Can an algebraic expression have more than one correct form?

Yes, an algebraic expression can have more than one correct form. This is because algebraic expressions can be simplified in different ways and still be equivalent. However, it is important to choose the most simplified form to make the expression easier to work with.

5. What is the purpose of using parentheses in an algebraic expression?

Parentheses are used in algebraic expressions to indicate the order of operations. This helps to clarify which operations should be performed first when simplifying the expression. It also helps to avoid confusion and ensure that the correct result is obtained.

Similar threads

  • Advanced Physics Homework Help
Replies
2
Views
829
  • Advanced Physics Homework Help
Replies
13
Views
2K
  • Calculus and Beyond Homework Help
Replies
10
Views
444
  • Advanced Physics Homework Help
Replies
1
Views
687
  • Advanced Physics Homework Help
Replies
19
Views
828
  • Advanced Physics Homework Help
Replies
6
Views
2K
  • Precalculus Mathematics Homework Help
Replies
7
Views
1K
  • Advanced Physics Homework Help
Replies
24
Views
2K
  • Advanced Physics Homework Help
Replies
5
Views
783
Replies
1
Views
804
Back
Top