In the expression 6:15 = X:45, the unknown X is equal to

Question

Quizplus · Accepted Answer

To solve proportions like this one, we can use cross-multiplication. This means we multiply the first term on the left-hand side by the second term on the right-hand side, and set it equal to the product of the second term on the left-hand side and the first term on the right-hand side.

So in this case, we have:

6:15 = X:45
Cross-multiplying gives: 
6 x 45 = 15 X 
Simplifying: 
270 = 15X 
Dividing both sides by 15: 
18 = X

So X must be 18. Therefore the answer is C.

In the Expression 6:15 = X:45, the Unknown X Is