20.( )能与6:8组成比例.
| A. | 3:4 | B. | 4:3 | C. | 3:8 | D. | 4:8 |
19.有一个数,万级是307,个级是496,这个数是( )
| A. | 3070496 | B. | 307496 | C. | 3074960 |
18.解方程.
0 132197 132205 132211 132215 132221 132223 132227 132233 132235 132241 132247 132251 132253 132257 132263 132265 132271 132275 132277 132281 132283 132287 132289 132291 132292 132293 132295 132296 132297 132299 132301 132305 132307 132311 132313 132317 132323 132325 132331 132335 132337 132341 132347 132353 132355 132361 132365 132367 132373 132377 132383 132391 199269
| 7x=1.54 | 6x+1.4=8 | 4.2x-2.16=1.2 | 20-x=9 |
| (x+3)×2=8 | 4.5÷x=1.5 | 2.4×3+8x=11.2 | 2x+3x=1.5×5 |