9.方程5.2×2x=20.8的解是( )
| A. | x=10.2 | B. | x=2 | C. | x=1.02 | D. | x=0.2 |
8.将一根长为x米的绳子一半再一半地剪去,剪了4次后,剩下的正好是2米,这根绳子原来长( )米.
| A. | 4 | B. | 8 | C. | 16 | D. | 32 |
7.老刘今年a岁,小刘今年(a-14)岁,再过c年后,他们相差的岁数是( )
0 132111 132119 132125 132129 132135 132137 132141 132147 132149 132155 132161 132165 132167 132171 132177 132179 132185 132189 132191 132195 132197 132201 132203 132205 132206 132207 132209 132210 132211 132213 132215 132219 132221 132225 132227 132231 132237 132239 132245 132249 132251 132255 132261 132267 132269 132275 132279 132281 132287 132291 132297 132305 199269
| A. | 14岁 | B. | c岁 | C. | (c+14)岁 |