Question

AB=6, AC=21, DF=35, EF=x

Answer 1

what do u need to know

Answer 2

what x is

Answer 3

16

Answer 4

\[\frac{ DE }{ EF }=\frac{ AB }{ BC }\] add 1 to both sides
\[\frac{ DE }{ EF }+1=\frac{ AB }{ BC }+1\]
\[\frac{ DE+EF }{ EF }=\frac{ AB+BC }{ BC }\]
\[\frac{ DF }{ EF }=\frac{ AC }{ BC }=\frac{ AC }{ AC-AB }\]
\[\frac{ 35 }{ EF }=\frac{ 21 }{ 21-6 }=\frac{ 21 }{ 15 }\]
\[EF=35 \times \frac{ 15 }{ 21 }=?\]

Answer 5

25

Answer 6

good