Answer:
The only options equivalent to 2:9 are B and C.
Explanation:
A ratio is a comparison between two or more numbers.
When two ratios are equivalent, they describe the same relationship between numbers.
An equivalent ratio is to a number is usually the same ratio in which the numerator and denominator (first and second number) have been multiplied by a common multiple.
To find if two ratios are equivalent, we have to put them in their simplest forms and compare.
The ratio we are comparing other ratios with is 2:9
So, we will put all other ratios in their simplest form and see if it gives us 2:9
A. 9:2 - This is already in its simplest form and it is not equal to 2:9.
B. 18:81 - To put this in simplest form, we divide both numbers by 9:
18:81 = 2:9
Hence, this is an equivalent ratio to 2:9.
C. 12:54 - To put this in simplest form, we divide both numbers by 6:
12:54 = 2:9
Hence, this is an equivalent ratio to 2:9.
D. 18:4 - To put this in simplest form, we divide both numbers by 2:
18:4 = 9:2
This is not the same as 2:9.
E. 20:45 - To put this in simplest form, we divide both numbers by 5:
20:45 = 4:9
This is not the same as 2:9.
The only options equivalent to 2:9 are B and C.