Answer:
x+2x+2=17
Step-by-step explanation:
I'm assuming that's what you're asking, so here is the answer explanation.
3x+6=21
3x=15
Hence, x=5
Apply x=5 to x+2x=2
5+10+2
=17
I think there is a .5 percent chance i added all numbers and divided by 6[the blue marbles]
I hope this helps you
DF^2+DC^2=FC^2
DF^2+15^2=39^2
DF^2=39^2-15^2
DF^2=24.54
DF=36
