Question

if 18,a,(b_3)are in Ap then a+b​

Answer 1

18, A, B, -3 are in AP

$a+3d=(-3)\\\\18+3d=(-3)\\\\3d=-3-18\\\\3d=-21\\\\d=-7$

a = 18

d = (-7)

1}

$a+d=A\\\\18-7=11\\\\A=11$

2}

$a+2d=B \\\\18 +2(-7)=B\\\\18-14=B\\\\B=4$

HENCE,

 $A=11\\\\B=4$

$11+4 = 15 \\\\A+B=15$

Hope it help u....