Answer :
Answer:
[tex]\boxed{225}[/tex]
.
Step-by-step explanation:
Arithmetic sequence
[tex]Un = a + (n - 1)b[/tex]
.
First step, find its difference
[tex]b = U_2 - U_1[/tex]
[tex]b = 6 - 3[/tex]
[tex]b = 3[/tex]
.
So, we get
[tex]a = 3[/tex]
[tex]b = 3[/tex]
.
Finally, Let's find the 75th term
[tex]U_{75} = 3 + (75 - 1)3[/tex]
[tex]U_{75} = 3 + (74)3[/tex]
[tex]U_{75} = 3 + 222[/tex]
[tex]U_{75} = 225[/tex]