Answer:
b) 5:7 = 15:21
Step-by-step explanation:
This questions tests our understanding of enlargement ratios.
#Determine the decimal equivalents or simplify to see which one is correct:
#a) 5:21 = 7:15
[tex]\frac{5}{7}=0.7143\\\\\frac{7}{15}=0.4667\\\\5:7\neq 7:15[/tex]
#b) 5:7 = 15:21
[tex]=\frac{5}{7}\\\\=\frac{15}{21}=\frac{5}{7} \# dividing \ by \ 3\\\\[/tex][tex]\frac{5}{7}=\frac{15}{21}[/tex]
#c) 5:7 = 21:15
[tex]\frac{5}{7}=0.7143\\\\\frac{21}{15}=1.4\\\\\frac{5}{7}\neq \frac{21}{15}[/tex]
#d) 21:5 = 15:7
[tex]\frac{21}{15}=1.4\\\\\frac{15}{7}=2.1429\\\\\frac{21}{15}\neq \frac{15}{7}[/tex]
Hence, option b is the correct one as 5:7 = 15:21
