Answer:
x=8
Step-by-step explanation:
Triangle DCE is similar to EGF
CE/EF=DE/EG
Substitute
(8x-1)/21=(6x+3)/17
Cross multiply
(8x−1)*(17)=(6x+3)*(21)
136x−17=126x+63
Subtract 126x from both sides
10x−17=63
Add 17 to both sides.
10x−17+17=63+17
10x=80
Divide both sides by 10.
x=8