Question

Solve the proportion 7/5=21/x (show work/explain how u got it please)

Answer 1

Answer:

x = 15

Step-by-step explanation:

I am going to use the "butterfly" method for proportions

(there is another type of butterfly method that is different, I am not sure if there is another name for this method, sorry!)

$\frac{7}{5} = \frac{21}{x}$

Multiply the:

- top left by the bottom right

-the top right by the bottom left

and then:

- set them equal to each other

So we will multiply 7 by x and 21 by 5 (if this doesn't make sense tell me and I will explain it even more!)

7x = 21 * 5

7x = 105

(Divide both sides by 7) x = 15

Hope this helps, have a nice day! :D <3