第9章 9.19

(1)

33x2>92x+1=32(2x+1)=34x+23^{3x-2} > 9^{2x+1} = 3^{2(2x+1)} = 3^{4x+2}

3x2>4x+2x<43x - 2 > 4x + 2 \qquad x < -4

(2)

4x2x222x2x20(2x2)(2x+1)0x14^x - 2^x \leq 2 \qquad 2^{2x} - 2^x - 2 \leq 0 \qquad (2^x - 2)(2^x + 1) \leq 0 \qquad x \leq 1

(3)

(0.25)x1.125(0.5)x+0.125<0(0.25)^x - 1.125(0.5)^x + 0.125 < 0

(0.5x0.125)(0.5x1)<00<x<3(0.5^x - 0.125)(0.5^x - 1) < 0 \qquad 0 < x < 3

解説: r31bn1z