13.
如图,已知∠BOF=120°,则∠A+∠B+∠C+∠D+∠E+∠F为多少度( )
| A. | 360° | B. | 720° | C. | 540° | D. | 240° |
9.
已知关于x的不等式2x-a>-3的解集在数轴上表示如图所示,则a的值等于( )
| A. | -1 | B. | 0 | C. | 1 | D. | 2 |
8.下列各式是一元一次不等式的是( )
0 282113 282121 282127 282131 282137 282139 282143 282149 282151 282157 282163 282167 282169 282173 282179 282181 282187 282191 282193 282197 282199 282203 282205 282207 282208 282209 282211 282212 282213 282215 282217 282221 282223 282227 282229 282233 282239 282241 282247 282251 282253 282257 282263 282269 282271 282277 282281 282283 282289 282293 282299 282307 366461
| A. | x2-3x+2>4x | B. | $\frac{1}{2}$x+2<x+3 | C. | $\frac{2}{x}$+1≤3x | D. | 2x+3=4x |