Answer:
8
Step-by-step explanation:
We can set this up in a ratio. In the picture shown, there is a large triangle and a small triangle inside it.
The ratio for the large triangle would be 21/28.
I got the '21' from '21/28' from doing 15+6.
Now the ratio for the small triangle is 6/x. As x is the unknown value.
To find x, we have to cross multiply and to do that we would do:
21x = 28x6
Simply and you get
21x=168
x=8
Hope this helps! :)
