1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lions [1.4K]
3 years ago
11

PLease solve this factorize: x^2-4x-21+10y-y^2

Mathematics
2 answers:
natita [175]3 years ago
5 0

Answer:

(x - y + 3)(x + y - 7)

Step-by-step explanation:

x^2 - 4x - 21 + 10y - y^2

= x^2 - y^2 +10y - 4x - 21

= (x - y)(x + y) + 10y - 4x - 21

This is a stab in the dark - I think this might factor to (x - y + 3)(x + y - 7)  or

(x - y - 7)(x + y + 3) - I think I've come across one like this before.

Lets try the first one:

(x - y + 3)(x + y - 7) = x^2 + xy - 7x - y^2 - xy +3y + 3x + 7y - 21

= x^2 -7x + 3x -21 + 10y  - y^2.

This is correct but isn't a very logical way to do this. There must be a better way!

The logical way is  by reducing the expression to the difference of 2 squares: (x - 2)^2 - (y - 5)^2

This factors to ( x + y -7)(x - y + 3).

kompoz [17]3 years ago
4 0

 

\displaystyle\bf\\x^2-4x-21+10y-y^2=\\=x^2-y^2 -7x+3x+7y+3y -21=\\\\=(x-y)(x+y) -7x+7y +3x+3y-3\cdot7=\\\\=\boxed{\bf(x+y-7) (x-y+3)}

 

You might be interested in
Please help 8th grade math
Zepler [3.9K]

Answer:

1500 calories

Step-by-step explanation:

2400 is 100% of in this case, 8/8

So then we know that 1/8 of 2400 is 300 because we just divide it by 8. Sarah eats 5/8 that much so we multiply 300 by 5 which gives us 1500

6 0
2 years ago
Read 2 more answers
Given:3^5n=3^5(3^2n)^2 <br><br> solve for n
katovenus [111]
The correct answer is 5. Take a look at the attachment to see how I got the solution. Hope this helps! :)

6 0
2 years ago
A woman traveled 2438.1 miles in 17 hours 20 minutes. Find the average speed of her light in miles per hour (Change 17 hours 20
adell [148]

Answer:

+140.68 m/h

Step-by-step explanation:

17.33 h

2438.1/17.33 = 140.68

+140.68 m/h

6 0
3 years ago
Find the associated reflex angle measure for an angle of 60°
sergij07 [2.7K]
The reflex angle is the other angle
see image below

so
reflex=360-angle
reflex=360-60=300
reflex angle=300

8 0
2 years ago
What is the slope of this graph?
liq [111]
Umm no you need to do your own work and do not be asking for answers
Nothing is handed to you ....you need to work HARD to get what you want.
6 0
3 years ago
Other questions:
  • What is 4 3/5 - 2 1/4
    9·1 answer
  • To increase a number by 4.6%, what single multiplier would you use
    15·1 answer
  • Multiply. State any excluded values.<br><br> q+5/-3 * -3q/q+2
    6·1 answer
  • What is the domain of the function?
    6·1 answer
  • What is the slope of this line?
    15·1 answer
  • 5) h=? ( show the work please)
    14·1 answer
  • Having trouble solving this:
    7·2 answers
  • Shelter A has a capacity of 300 beds and is 70% occupied. Shelter B is 35% occupied. The ratio of the occupancy of shelter A to
    8·1 answer
  • Which expression is equal to 5 + 4 X 2 - 6?
    8·2 answers
  • What is a severe limitation of using the Internet for primary research? The data on the Internet are usually outdated. The educa
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!