Answer:
7:5 is equivalent to 21:15
Step-by-step explanation:
Ratio M:N is represented by the fraction M/N
So 7:5 is represented as 7/5
Let the unknown in the second ratio be x
Then we have the equivalent ratio 21:x which can be represented as 21/x
Since these ratios are equivalent we get
[tex]\dfrac{7}{5} = \dfrac{21}{x}\\\\[/tex]
Multiply throughout by x:
[tex]\dfrac{7}{5} x = 21[/tex]
Multiply throughout by [tex]\dfrac{5}{7}[/tex]
[tex]\dfrac{7}{5} x \cdot \dfrac{5}{7} = 21 \cdot \dfrac{5}{7}\\\\[/tex]
[tex]x = 15[/tex]
The second ratio is 21/15 or 21:15
So the completed statement is
7:5 is equivalent to 21:15
