Question

If 18,a,b,-3 are in A.P.then find a+b ?

Answer 1

Answer:

15

Step-by-step explanation:

18,a,b,-3

a,a+d,a+2d,a+3d

step 1:

a+3d=-3

18+3d=-3

3d=-3-18

3d=-21

d=-21/3

d=-7

step 2:

a+d

=18+(-7)

=18-7

=11

a=11

a+2d=b

18+2(-7)=b

b=4

therefore:a+b=11+4

=15//