Answer:
[tex]\bold{d=\dfrac{13}4=3\dfrac14}[/tex]
Step-by-step explanation:
[tex]a_{10}\,,\ _{\{+d\}}\ \ a_{11}\,,\ _{\{+d\}}\ \ a_{12}\,,\ _{\{+d\}}\ \ a_{13}\,,\ _{\{+d\}}\ \ a_{14}\quad\implies\quad\ a_{14}-a_{10}=4d\\\\4d=a_{14}-a_{10}\\\\4d=30-17\\\\4d=13\\{}\ ^{\div4\quad\div4}\\d=\dfrac{13}4=3\dfrac14[/tex]