SOLUTION: What is the fraction? So, that it is equivalent to the fraction with the indicated denominator. 5/7 = ?/21

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: What is the fraction? So, that it is equivalent to the fraction with the indicated denominator. 5/7 = ?/21       Log On


   

Question 4955: What is the fraction? So, that it is equivalent to the fraction with the indicated denominator.
5/7 = ?/21


Answer by Hungryfrog(2) About Me  (Show Source):
You can put this solution on YOUR website!
You can solve these types of questions by cross-multiplying.
So --> 5 x 21 = 7 x n (I substituted n for ?)
That comes out to 105 = 7 n
Then you can divide each side by 7 to solve for n:
15 = n
So, you can rewrite it as 5/7 = 15/21
Those two fractions are equivalent.