Find the value of x.
x / x+5 = x-4 / x
the book says the answer is 20, but im not getting that. I crossed multiplied and got x^2=(x+5)(x+4) and then multiplied that out x^2 = x^2 + 9x+ 20 and then 9x=20.. what am I doing wrong?
those are proportions by the way
little mistake
you got x²=(x+5)(x-4)
oooooh! i was wondering what i did. thank you =]
To find the value of x in the equation:
x / (x + 5) = (x - 4) / x
You correctly cross-multiplied to eliminate the fractions, but there seems to be a mistake in your calculations afterward. Let's go step-by-step to solve the equation correctly:
1. Cross-multiplying the equation gives you:
x * x = (x + 5) * (x - 4)
Therefore, x^2 = x^2 + x - 20 (expand the right side).
2. Next, let's simplify the equation by canceling out x^2 on both sides:
0 = x - 20
3. We can now isolate x by moving the constant term to the other side of the equation:
x = 20
So, the value of x is indeed 20, as stated in the book. It seems that the mistake occurred when you canceled out x^2 incorrectly.