Answer: 27
Step-by-step explanation:
Given
In the first sequence, the first term is [tex]a_1=15[/tex]
Common difference is [tex]d_1=4[/tex]
In the second sequence, the first term is [tex]b_1=18[/tex]
Common difference is [tex]d_2=3[/tex]
The nth term of the sequence is [tex]a_n=a+(n-1)d[/tex]
for the same number to appear on both sequence, the nth term must be equal
[tex]\Rightarrow 15+(n-1)4=18+(n-1)3\\\Rightarrow 3=(n-1)\\\Rightarrow n=4[/tex]
Put n=4
[tex]\Rightarrow 15+(4-1)4\\\Rightarrow 15+12=27[/tex]
Therefore, 27 is the first common term in both sequences.
