Question

If y= x+3/6-x, what is the value of y when x =7i?

Answer 1

Option (2)

Explanation:

Given : y =
`(x+3)/(6-x)`

If x = 7i

y =
`(7i+3)/(6-7i)`

By simplifying denominator of the given rational expression,

y =
`(7i+3)/(6-7i)* (6+7i)/(6+7i)`

y =
`((7i+3)(6+7i))/(6^2-(7i)^2)`

y =
`(7i(6+7i)+3(6+7i))/(36-49i^2)`

y =
`(42i+49i^2+18+21i)/(36+49)` [Since, i² = (-1)]

y =
`(63i-49+18)/(85)`

y =
`(63i-31)/(85)`

y =
`-(31)/(85)+(63)/(85)i`

Therefore, Option (2) is the correct option.