I need help with an algebra problem?

Question

i was given this problem:

1/4 = 3 - ((2x-1)/(x+2)) and solve for x:
i get x = -8.666 but it doesnt check out right when i plug it back into the original equation for x.
can someone tell me what x is?
and show me how they came to that answer?

Answer 1

1/4 = 3 - (2x - 1)/(x + 2)...Multiply thro` by (x + 2):

(x + 2)/4 = 3(x + 2) - (2x - 1) Multiply thro` by 4:

(x + 2) = 12(x + 2) - 4(2x - 1)...Expand:

x + 2 = 12x + 24 - 8x + 4.......Simplify:

x + 2 = 4x + 28, so

-3x = 26, so

x = -26/3.

Check:

3 - (-52/3 - 1)/(-26/3 + 2)

=3 - (-55/3)/(-20/3)

= 3 - (55/3 x 3/20)


=3 - (55/20)

=3 - 11/4

= 1/4.

So, your answer was correct: I suspect that you made a mistake when you substituted your answer back into the original equation... I found the substitution a bit confusing too!

Hope this helps, Twiggy

Answer 2

I'm sure you have the obtained the correct answer (it's -26/3, exactly) so, unless you're just talking about roundoff error (that is, if you plug -8.666 into the right side of the original equation, you get 0.24992499..., not 0.25), you must have made a calculation error in your check.

Answer 3

1/4 = 3 - ((2x-1)/(x+2))
(2x-1)/(x+2) = 3 - 1/4
On cross multiplication we get -
11 x + 22 = 8x - 4
3 x = - 26
x = - 26 / 3 = - 8. 66667 ..............Answer

Answer 4

To solve for x, you need to get x by itself.

First, you need to subtract three from both sides.

(.25)-3=-((2x-1)/(x+2))
-2.75=-((2x-1)/(x+2))

Since both sides are negative, you can cancel them out.

2.75 = ((2x-1)/(x+2))

Now you need to multiple both sides by (x+2).

(2.75)(x+2)=2x-1

2.75x+5.5=2x-1

Subtract (2.75x) from both sides and add 1 to both sides to bring x toward being by itself on one side again.

(5.5)+1=2x-2.75x

6.5 = -0.75x

Divide both sides by -0.75.

6.5/(-0.75)=x

x=-8.67

huh. I don't know why it didn't work when you plugged it in. Maybe make sure you are applying the signs properly.

Answer 5

the answer is -8.666 you must be checking wrong