Video: Finding the Unknown in a Proportion

Bethani Gasparine

If 66/𝑥 = 0.75, find the value of 𝑥.

01:16

Video Transcript

If 66 divided by 𝑥 is equal to 0.75, find the value of 𝑥.

There are a couple of ways to solve this problem. One option would be to get rid of 𝑥 on the bottom. So we would multiply both sides of the equation by 𝑥. This way, on the left-hand side, they would cancel. So we have 66 equals 0.75𝑥. And to solve for 𝑥, we would need to divide by 0.75 to both sides. They cancel on the right. And then on the left, 66 divided by 0.75 is 88. So the value of 𝑥 is 88.

Another option would be to take the 0.75 and write it as a fraction. 0.75, seven is in the tenths place and five is in the hundredths place. So we could change 0.75 to be 75 over 100. And then we could cross multiply and solve for 𝑥. 66 times 100 is 6600. And 75 times 𝑥 is 75𝑥. And now we divide both sides by 75. The 75s cancel on the right. And then 6600 divided by 75 is once again 88. So finally, our value of 𝑥 would be 88.

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.