如图的图象表示甲、乙两辆汽车行驶的时间和路程的关系．
20．计算下面各题，能简算的要简算．
0 157214 157222 157228 157232 157238 157240 157244 157250 157252 157258 157264 157268 157270 157274 157280 157282 157288 157292 157294 157298 157300 157304 157306 157308 157309 157310 157312 157313 157314 157316 157318 157322 157324 157328 157330 157334 157340 157342 157348 157352 157354 157358 157364 157370 157372 157378 157382 157384 157390 157394 157400 157408 199269
| $\frac{13}{5}$×$\frac{7}{9}$+$\frac{2}{5}$÷$\frac{9}{7}$ | $\frac{1}{12}$+$\frac{1}{4}$×$\frac{4}{5}$-$\frac{1}{4}$ | （$\frac{12}{17}$-$\frac{8}{13}$）×$\frac{1}{4}$+$\frac{14}{17}$ |
| 10.1×8.7 | $\frac{1}{3}$÷[（$\frac{2}{3}$+$\frac{1}{5}$）×$\frac{1}{13}$] | 27.3-4.02-5.98 |