Step-by-step explanation:

<h3><u>Supposition of Terms in an A.P.</u></h3>
<h3>(1) Three terms as : a -d, a,a + d .</h3><h3>(2) Four terms as : a -3d , a - d , a + d , a + 3d .</h3><h3>(3)Five terms as : a -2d , a - d , a , a+ d, a + 2d.</h3>
To know the solution with Proof
Refer To the above attachment .
<h2>Hope this helps you !! </h2><h2>Carry on learning!!</h2>