9. ABC and DEF are similar triangles. Find the measure of BC.
Please help!

Check the picture below.

let's change the decimal amounts to fractions, so for 3.5 let's use 7/2 and for 1.5 let's use 3/2, let's use the proportion on the left side and then the next one after

now, let's notice that we didn't use the 2x+11, since that gives us a negative "x" and "x" cannot be a negative value.

my answer got deleted but it's a

step-by-step explanation:

part a: 1.08

part b: 27.59