Answer
4,11,25,53
Work Step by Step
To find the first four terms of the sequence whose general term is $a_{n}$ =2$a_{n-1}$ + 3, we replace n in the formula with 2,3, and 4.
n=1, $a_{1}$ = 4
n=2, $a_{2}$ =2$a_{2-1}$ + 3= 2$a_{1}$ + 3
Substitute $a_{1}$ as 4
$a_{2}$ =2*4 + 3 = 8+3 = 11
n=3, $a_{3}$ =2$a_{3-1}$+ 3 = 2$a_{2}$+ 3
Substitute $a_{2}$ as 11
$a_{3}$ = 2*11 + 3= 22+3 = 25
n=4,$a_{4}$ =2$a_{4-1}$+ 3= 2$a_{3}$+3
Substitute $a_{3}$ as 25
$a_{4}$ =2*25 + 3 = 50+3 =53
The first four terms are 4,11,25,53
