Question

if the terms 7,a,a,63 are in proportion then a is what

Answer 1

$hey \: mate \: \\ here \: is \: your \: answe \\ \\ 7... \: ...63 \\ \\ 7 = a + (1 - 1) \times d \\ 7 = a + d \\ 63 = a + (4 - 1) \times d = \\ 63 = a + 3d \\ \\ taking \: both \: frist \: and \: second \: \\ we \: got \\ \\ a + d = 7 \\ a + 3d = 63 \\ - \: \: \: - \: \: - - \\ - - - - - - \\ - 2d = - 56 = 2d = 56 \\ d = 28 \\ \\ a2 = a + (n - 1) \times d \\ = 7 + (2 - 1) \times 28 \\ = 7 + 28 = 35 \\ \\ a3 = a + (n - 1) \times d \\ = 7 + (3 - 1) \times 28 \\ = 7 + 2 \times 28 \\ = 7 + 56 = 63 \\ \\ a2 = 35 \: and \: a3 = 63$