Question

-1,X,7 are the 3 terms of A.P,then X=____​

Answer 1

$a1 = a = - 1 \\ a3 = 7$

a3 = 7

a + 2d = 7

- 1 + 2d = 7

2d = 7 + 1

2d = 8

d = $\ \frac{8}{2}$

d = 4

x = a2 = a + d

x = -1 + 4

x = 3