Question

Is the sequence - 10, – 4, 2, 8, ... is an A.P.? Find the 31st term, if it is an A.P.​

Answer 1

Answer:

Let first term of Ap is a and common difference is d

use formula

tn=a+(n-1) d

now

t11=a+(11-1) d=a+10d=38

same way

t16=a+15d=73

solve this equation then

a=-32 and d=7

now t31=a+30d=-32+210=178

Answer 2

Answer:

yes, the sequence is A.P. and the value of the 31st term is 170

Step-by-step explanation:                                                

1st term of the A.P. is -10                      ;     d = -4-(-10) = -4+10 = +6                              

    Hence , the 31st term will be = a+(n-1)d

                                                     = -10+ (30×6)    

                                                     = -10+180

                                                     = 170