35.0k views
0 votes
X/x+2 = 4/5. Solve for x.

2 Answers

5 votes
Hey!

First, let's write the problem.

(x)/(x)+2=(4)/(5)
Since the least common multiple is 5x, we are going to multiply by that.

(x)/(x)\cdot \:5x+2\cdot \:5x=(4)/(5)\cdot \:5x

5x+10x=4x

15x=4x
Subtract 4x from both sides.

15x-4x=4x-4x

11x=0
Divide both sides by 11.

(11x)/(11)=(0)/(11)

Our final answer would be,

x=0

This tells us that this problem has no solution.

_________

Your problem may have been written like this,

(x)/(\left(x+2\right))=(4)/(5)
If so, there's a totally different solution, which is why important to include parenthesis. Let's simplify it.
Cross multiply. It would look something like this,

x\cdot \:5=\left(x+2\right)\cdot \:4
Apply the distributive property.

x\cdot \:5=4x+8
Subtract 4x from both sides.

x\cdot \:5-4x=4x+8-4x
This tells us that our final answer would be,

x=8

Thanks!
-TetraFish
User Joseph Izang
by
8.4k points
2 votes
X/x+2 = 4/5

5x = 4x + 8

5x - 4x = 8

x= 8


User Federico Sierra
by
7.9k points