Question

in an ap if S5 + S7 equal to 1 6 7 and S10 equal to 235 then find the AP where sn is denoted the sum of its first n term plz plz guys give me answer plz

Answer 1

first term is 1 and common difference is 5

Answer 2

S5+S7=167
5/2(2a+4d) + 7/2(2a+6d)=167
5/2×2(a+2d) +7/2×2(a+3d)=167
5a+10d +7a+21d=167
12a+ 31d =167. _(1)

S10= 235
10/2 {2a+ (10-1)d}=235
5(2a+9d)=235
2a+9d=47. _(2)


12a+31d=167. _(1)
2a+9d=47.
_(2)
aage linear equation process se kosis kijie