Question

For what value on n are the nth term of two aps 15,12,19.......and-15,-13,-11 ........equal

Answer 1

[15+(n-1)×-3]=[-15+(n-1)×2],

15-3(n-1)=-15+2(n-1),

15+15=2(n-1)+3(n-1),

30=5(n-1),

6=(n-1),

then

6+1=n,

n=7