# Video: Solving Equations with an Unknown in the Denominator

Solve 125/(𝑥 + 3) = 5.

01:43

### Video Transcript

Solve 125 divided by 𝑥 plus three equals five.

Our first step is to multiply both sides of the equation by 𝑥 plus three. This gives us 125 is equal to five multiplied by 𝑥 plus three. Expanding or multiplying out the bracket or parenthesis gives us five 𝑥 plus 15 as five multiplied by 𝑥 is five 𝑥 and five multiplied by three is equal to 15. This means that 125 is equal to five 𝑥 plus 15.

Our next step is to subtract 15 from both sides of the equation. This gives us five 𝑥 is equal to 110. Finally, dividing both sides by five gives us an answer of 𝑥 equals 22. Therefore, the solution to the equation 125 divided by 𝑥 plus three equals five is 𝑥 equals 22.

We can check this answer by substituting 𝑥 equals 22 into the initial equation. Substituting this in gives us 125 divided by 22 plus three. 22 plus three is equal to 25. So we are left with 125 divided by 25. As this is equal to five, the right-hand side of the question, we can say that 𝑥 is definitely equal to 22.