Question #86fb5

1 Answer
Jan 17, 2018

x = 2/3

Explanation:

The formatting is kind of unclear, but I'm assuming the equation is:
1/2 - 3/(x+3) = 5/(2(x+3)) - 1

First, we will add one to both sides to simplify it:
1 + 1/2 - 3/(x+3) = 5/(2(x+3)).
Notice that 1 + 1/2 = 3/2 and that we can add 3/(x+3) to both sides:
3/2 = 5/(2(x+3)) + 3/(x+3).

Focusing on the side with the variable x, we can cross-multiply in order to get one common denominator and therefore, we can add the numerators:
[5/(2(x+3)) * (x+3)/(x+3)] + [3/(x+3) * (2(x+3))/(2(x+3))]
Proceeding with the multiplication, i.e. distributing everything, we will get:
(5(x+3))/(2(x+3)^2) + (6(x+3))/(2(x+3)^2).

Notice that both the numerator and denominator share a (x+3) so we can simply cancel them out and get:
3/2 = (5+6)/(2(x+3)).

If we proceed via multiplying both sides by two, to get rid of the twos in the denominators, we will get 3 = 11/(x+3).

Then we multiply both sides by (x+3) so we can have our unknown in the numerator: 3(x+3) = 11 which is equivalent to 3x + 9 = 11.

Proceed with simple algebra, and we will get that x = 2/3.

Checking this, we can see it is the answer.