answer algebra problem - edited to make more clear?

Question

apparently I didn't clarify last time what I meant... it is 2 over 5 PLUS 4 over 10x+5 EQUALS 7 over 2x+1 --- sorry for confusion... can someone help me?!?!?!

(2/5) + (4/10x+5) = (7/2x+1) ...solve for X ... show wrk pls so I know what I'm doing wrong!! I think my answer manual was wrong, but not sure... so I need help knowing exactly what to do and how to get the correct answer. Thanks so much!!

Answer 1

It's equations like this that show the limitations of Yahoo Answers. But I'll give it a try:
First, multiply both sides by (2x+1):
(2x+1)(2/5) + (2x+1)(4/(10x+5)) = 7

Multiply out, and re-arrange the 10x+5 to get:
(4x+2)/5 + 4(2x+1)/(5(2x+1)) = 7
4x/5 + 2/5 + 4/5 = 7
AS LONG AS 2x+1 DOES NOT EQUAL ZERO

4x = 7 - 2/5 - 4/5 = 7 - 6/5 = 5 4/5 or 29/5
x = 29/5 * 1/4

x = 29/20

Answer 2

Gosh the way you present things here makes things hard. This is what I assume you have

2/5 + 4/(10x+5) = 7/(2x+1)

So lets group the x on one side

2/5 = 7/(2x+1) - 4/(10x+5)

also expressed as:

7/(2x+1) - 4/(10x+5) = 2/5

So now we add the two fractions on the left by finding the common denominator. (2x+1) (10x+5)


(7/(2x+1)) * 1 - (4/(10x+5)) *1 = 2/5

(7/(2x+1)) * (10x+5)/ (10x+5) - (4/(10x+5)) *(2x+1)/(2x+1) = 2/5

(7 * (10x+5) - 4 * (2x+1)) / ((2x+1) * (10x+5)) = 2/5

(70x + 35 - 8x - 4)/ 20x^2 + 20x + 5 = 2/5

70x + 35 - 8x - 4 = 2/5 * (20x^2 +20x +5)

Simplifying left and right side gives

62x + 31 = 8x^2 + 8x + 2

8x^2 - 54x - 29 = 0



Solve this using the quadratic equation:

x = -(-54) +/- sqrt (54^2 - 4 * 8 * -29) /(2*8)

x = (54 +/- sqrt (2916 + 928)) / 16

x = (54 +/- 62) / 16

x = 116/16 or -8/16 which is also -1/2
I don't know if this anwer is correct but put it back into the original equation to see if you get it correct.

Answer 3

work it out one piece at a time....

(2/5) + (4/(10x+5))=(7/(2x+1))

i suggest you start by multiplying both sides by one of the denomiators containing an x value (either (10x+5) or (2x+1))

work that through and re-write what you get....

i dont want to just give you the answers, but if you want to more help with the remaing steps, you can text me and i'll help you work it out ... feel free to text me at 513-205-8470 for help!

good luck

Answer 4

(2/5) + (4/10x + 5) = 7/2x + 1); solve for x.

Solution;

Resolving the factors,
we will have 0.4 + 0.4x + 5 = 3.5x +1,
and then , 0.4x + 5.4 = 3.5x +1-----(1)
then by separating known from unknown by adding (-3.5x -0.4) on both sides to keep it true and still equal,
goes like this (-3.5x-5.4)+(0.4x+5.4) = (-3.5x-5.4)+(3.5x+1)
and we will have
-3.10x = -4.4 ---------------------------(2)
and by multiplying both sides by -1/3.10,
goes like this (-1/3.10)(-3.10x) = (-1/3.10)(-0.6),
and we will have the answer which is
x = 0.1935 or x = 0.20-----------answer