Question

2^x + 2^x+1 + 2^x+2 + 2^x+3 = 15/2

Answer 1

2ˣ + 2ˣ⁺¹ + 2ˣ⁺² + 2ˣ⁺³ = 15/2
2ˣ + 2ˣ.2¹ + 2ˣ.2² + 2ˣ . 2³ = 15/2  (2ˣ = y)
y + y.2 + y.4 + y.8 = 15/2
y + 2y + 4y + 8y = 15/2
3y + 12y = 15/2
15y = 15/2
2.15y = 15
30y = 15
y = 15/30
y = 1/2

y = 2ˣ
1/2 = 2ˣ
2⁻¹ = 2ˣ
x = -1