(河北区)求未知数x的值. (1)1.5x+3x="9" (2)2x.
3.35×6.4×2+6.7×3.6 18.7-3.375-6.625
125×(8+0.8+0.08) 45÷〔78-(25+38)
1.3-3.79+9.7-6.21 8×0.4×12.5×2.5
19175÷59+678 36.5×1.4-8.51
()÷20-[(