3^x+3^{x+1}-36=0

解答

3^{x} + 3^{x + 1} - 36 = 0

x = 2

求解步骤

3^{x} + 3^{x + 1} - 36 = 0

因式分解

3^{x} + 3^{x + 1} - 36 : 4 (3^{x} - 9)

4 (3^{x} - 9) = 0

使用零因数法则： If

ab = 0

then

a = 0

b = 0

3^{x} - 9 = 0

解

3^{x} - 9 = 0 : x = 2

x = 2

so l v e f or i, 2^{i} n = 2

22 = e^{x - 3} + e^{- (x - 3)}

4665 6^{2 x - 6} = 3 6^{x - 12}

4^{(2 x - 5)} = 64

4^{x^{2} + 3 x + 3} = 2^{2}