Question

if 18,a,b,-3 are in a ap then find a+b

Answer 1

given
18,a,b,-3
they are in ap then
t2-t1=t4-t3
a-18= -3-b
a+b= -3+18
a+b=15 is answer obtained

Answer 2

HERE IS YOUR ANSWER...⬇⬇

$\underline{SOLUTION}$ ➡

$Given ,\\ \\ 18 \: ,a \: ,b \:, - 3 \: \: \: \: \: are \: in \: a \: \: \: A.P \\ \\ To \: find \: : \: a + b$

$Here \: ,\\ \\ t1 = 18 \\ \\ t2 = a\\ \\ t3 = b \\ \\ t4 = - 3$

$Now, \\ \\ 18 \:, a \: b, \: \: and \: - 3 \: \: \: \: \: \: are \: in \: \: \: A.P$

$So$

$t2 - t1 = t4 - t3 \\ \\ = > a - 18 = - 3 - b \\ \\ = > a + b = - 3 + 18 \\ \\ = > a + b = 15$

$\underline{ANSWER}$➡

$a + b = 15$

✝✝ $\pink{....THANK \: YOU....}$ ✝✝