The values of x which satisfy the equation 5^{1+x} + 5^{1–x} = 26 are

- –1, 1
- 0, 1
- 1, 2
- –1, 0

**Answer**

5^{1+x} + 5^{1–x} = 26

5.5^{x} + 5.5^{-x} = 26

Let 5^{x} = t

5(t + 1/t) = 26

5(t^{2} + 1) = 26t

5t^{2} - 26t + 5 = 0

5t^{2} - 25t - t + 5 = 0

5t(t - 5) - (t - 5) = 0

(t - 5)(5t - 1) = 0

t = 1/5, 5

5^{x} = 1/5, 5

x = -1, 1

**The correct option is A.**