See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

Tutor:
New! Get regular updates about newly solved problems via algebra.com's RSS system.

Recent problems solved by 'xen0gears'

xen0gears answered: 3 problems
Linear-equations/1728: how can i get the solution of /4x-6/=5

1 solutions

Answer 718 by xen0gears(3) About Me  on 2005-05-10 20:01:53 (Show Source):
You can put this solution on YOUR website!
I'm guessing you mean the absolute value of (4x - 6) when you type /4x-6/
To solve this equation, you solve the following two equations:
4x-6 = 5 and 4x-6 = -5
You do this because |5| = 5, and |-5| = 5.
The first one gives 4x = 11, which means x = 11/4.
The second one gives 4x = 1, which means x = 1/4.
So x = 11/4, or x = 1/4.


Rectangles/1740: Start with a square. Double its base, then shrink its height by 3inch. The new rectangle's area is 40 square inches loarger than the area of the original square. How long are the sides of the square?
1 solutions

Answer 717 by xen0gears(3) About Me  on 2005-05-10 19:58:59 (Show Source):
You can put this solution on YOUR website!
(Please ignore all dotted lines [---] in the pictures. They are there so the picture would come out right.)
Suppose your original square has side length x:
_____
|-------|
|-------| x
|_____|
x (not to scale)
Then its area is +x%5E2+. Doubling the base gives the following shape:
__________
|-------------|
|-------------| x
|__________|
2x (not to scale)

Shrinking the height by 3 inches gives the following shape:

__________
|-------------| x-3
|__________|
2x (not to scale)

The area of this new rectangle is +2%2Ax%2A%28x-3%29+=+2x%5E2+-+6x+.
This area is 40 square inches larger than the area of the original square.
Recall that the area of the original square is +x%5E2+.
This gives us the equation +x%5E2+%2B+40+=+2x%5E2+-+6x+.
Subtracting +x%5E2+ from both sides gives +40+=+x%5E2+-+6x+.
Then we subtract 40 from both sides to get +0+=+x%5E2+-+6x+-+40+.
We can factor this into +0+=+%28x-10%29%2A%28x%2B4%29+, which means x = 10 or
x = -4.
Since x represents the length of the side of a square, x cannot be less than zero. Hence, x = 10 inches.


Quadratic_Equations/1752: a) Jim is going to put new carpet in his bedroom. Jim's bedroom is 10ft. by 12ft. How many square feet of carpet does he need?
b)Jim also needs some new base bored to go around the room. How much does he need?
1 solutions

Answer 714 by xen0gears(3) About Me  on 2005-05-10 19:47:44 (Show Source):
You can put this solution on YOUR website!
When finding the amount of square feet needed to cover a room, you should find the area of the given room. In this case the room is 10ft by 12ft, so the area is +10+%2A+12+=+120+ft%5E2+.
The second part is asking how many feet of base board you need to cover the perimeter of the room. The perimeter P of a rectangular room is given by +P+=+2%2Aa+%2B+2%2Ab+, where a and b are the lengths of the sides. In this case, a = 12ft and b = 10ft (you could reverse these but it doesn't matter), so the perimeter P is +P+=+2%2A12+%2B+2%2A10+=+24+%2B+20+=+44+ft+. So Jim needs 44ft of base board.