Question

The 1st term and the 40th term of the A.P., whose 7th
term is 34 and 15th term is 74 are​

Answer 1

Step-by-step explanation:

given a7=a+6d=34 and a15=a+14d=74

let us find d first

a+14d=74

a+ 6d=34

by subtracting them we will get

8d=40 d =40/8 =5 d =5

now substitute that in any of above equation a+6d=34 a+6×5=34

a+30=34, a= 34-30 a=4

now 1st term =a=4

40th term =a+39d=4+39×5

4+195=199

therefore 1st term is 4 and 40th term is 199