Answer:
solution given a-d ,a, a+d, a+2d are in A.P
according to the question
sum of 4 terms =12
a-d+a+a+d+a+2d=12
4a+2d=12
2a+d=12/2
d=6-2a
again
3rd + 4rt term =14
a+d+a+2d=14
2a+3d=14
substituting value of d
2a+3(6-2a)=14
2a+18-6a=14
18-14=4a
a=4/4=1
d=6-2×1=4
first term =a-d=1-4=-3
second term =a=1
third term =a+d=1+3=4
forth term =a+2d=1+3×2=7
n+5=15/2
n+5=7.5
n=7.5-5
n= 2.5
y = -5/4x -8
Step-by-step explanation:
There is a y-intercept of -8
There is a slope of -5/4
