3.84与56的和除以28与26的差,商是多少?正确列式是( )
A. | 84+56÷28-26 | B. | (84+56)÷(28-26) | C. | (84+56)÷28-26 |
19.三个数的积为正数,那么这三个数中负因数的个数是( )
0 158199 158207 158213 158217 158223 158225 158229 158235 158237 158243 158249 158253 158255 158259 158265 158267 158273 158277 158279 158283 158285 158289 158291 158293 158294 158295 158297 158298 158299 158301 158303 158307 158309 158313 158315 158319 158325 158327 158333 158337 158339 158343 158349 158355 158357 158363 158367 158369 158375 158379 158385 158393 199269
A. | 1个 | B. | 2个 | C. | 3个 | D. | 0个或2个 |