(1)30X÷2=360,
30X÷2×2=360×2,
30X=720,
30X÷30=720÷30,
X=24;
(2)2.3X-1.02=0.36,
2.3X-1.02+1.02=0.36+1.02,
2.3X=1.38,
2.3X÷2.3=1.38÷2.3,
X=0.6;
(3)8X-16=(X+1)×2,
8X-16=2X+2,
8X-16+16=2X+2+16,
8X=2X+18,
8X-2X=2X+18-2X,
6X=18,
6X÷6=18÷6,
X=3;
(4)根据线段图,列方程为:
4.5x-3x=13.5,
1.5x=13.5,
1.5x÷1.5=13.5÷1.5,
x=9;
(5)设底为x厘米,由三角形面积公式得:
12x÷2=144,
12x÷2×2=144×2,
12x=288,
12x÷12=288÷12,
x=24.
答:底为24厘米.