Answer:
1. Proportional
2. Not proportional
3. Proportional
Step-by-step explanation:
We have three questions with 2 ratios and are asked if they are proportional or not.
To define proportionality, basically its if the two ratios equal the same value when put in a certain way.
And that way is :
[tex]\frac{x}{y} =\frac{x}{y}[/tex]
You will substitute the numbers with the letters, in which you will cross multiply :
[tex]\frac{x * y}{x*y}[/tex]
So subtitute :
1.
[tex]\frac{1}{3} *\frac{7}{21}[/tex]
[tex]\frac{1*21}{7*3}[/tex]
[tex]21=21[/tex]
Therefore 1. is proportional.
2.
[tex]\frac{3}{4} *\frac{24}{18}[/tex]
[tex]\frac{4*24}{3*18}[/tex]
[tex]\frac{96}{54}[/tex]
96 = 54
Therefore 2. is not proportional.
3.
[tex]\frac{1}{5} *\frac{6}{30}[/tex]
[tex]\frac{1*30}{5*6}[/tex]
[tex]\frac{30}{30}[/tex]
30 = 30
Therefore 3. is proportional.
