Find an Online Tutor Now

L O.

asked • 03/29/14

help solving solutions

 
1.  Simplify    x-y    +    x+y
                    x+y          x-y
 
 
I have zero since x-y crosses out x-y and x+y crosses out x+y
 
 
2.  solve 12x^2 + 7x = 10
    
I am trying to use (-3x + 4) (-4x + 3)
 
3.  simplify    x^2 -5x + 4
                      x -1
 
  my answer is x - 4.  Is this correct?
 
4.  simplify  9x^2 - 3x
                     3x
 
 my answer is 3x-1.  Is this correct?
 
 

4 Answers By Expert Tutors

By:

Steve S. answered • 03/29/14

Tutor
5 (3)

Tutoring in Precalculus, Trig, and Differential Calculus

Steve S.

This "(12x^2 - 8x) (+ 15x - 10)" implies multiplication of two numbers, which is wrong.
It should be "(12x^2 - 8x) + (15x - 10)", the addition of two numbers.
Report

03/29/14

Stephen W.

tutor
Maybe technically, but since the binomials are multiplied later to equal zero, I felt this would not be useful for the student to understand the problem. In fact, I felt it would distract from learning, in this case. Different techniques. Hopefully she gets it, one way or the other.
Report

03/29/14

L O.

Would my answer still be 2/3 and -5/4  ??
Report

03/29/14

Stephen W.

tutor
In this case, yes, if the whole "technically they are added" doesn't confuse you. Sometimes the first term in the second parenthesis is a negative, and it impacts the problem dramatically, which is why I skipped over that. After all, you needed help on this specific problem, not theoretical problems that may come your way.
Congrats for figuring out the other solution! It sounds like you are getting it. 
Report

03/29/14

L O.

thank you for your help
Report

03/29/14

L O.

For problem #1
 
x-y/x +y   +  x+y/x-y,  I got 2+2=4   (Is this correct?)
Report

04/04/14

Stephen W.

tutor
The final answer is 2(x2 + y2)/ (x2 - y2)
Sorry for any confusion!
Report

04/04/14

L O.

Thank you very much I think I now understand
Report

04/05/14

Melissa A. answered • 03/29/14

Tutor
5.0 (34)

Homeschool Mom Available For Tutoring

Parviz F. answered • 03/29/14

Tutor
4.8 (4)

Mathematics professor at Community Colleges

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.