Answer:
x = 27
Step-by-step explanation:
solving similarities using equations:
→[tex]\frac{CD}{QD} = \frac{RD}{BD}[/tex]
→ [tex]\frac{x}{39} = \frac{18+x}{26+39}[/tex]
→ [tex]\frac{x}{39} = \frac{18+x}{65}[/tex]
→ 65(x) = 39(18+x)
→ 65x = 702 + 39x
→ 65x - 39x = 702
→ 26x = 702
→ x = 27
