15.能简算的要简算.
$\frac{1}{7}×8÷\frac{1}{7}$×9 | $\frac{5}{8}×2-\frac{5}{8}×\frac{8}{9}$ | $\frac{5}{13}×\frac{1}{5}+\frac{4}{5}×\frac{5}{13}$ |
$\frac{5}{6}-\frac{7}{12}×\frac{15}{14}$ | 6÷$\frac{6}{7}+\frac{6}{7}×\frac{1}{6}$ | $[\frac{7}{8}-(\frac{1}{3}+\frac{1}{6})]÷\frac{4}{9}$. |
14.解方程:
$\frac{2}{3}-\frac{1}{6}$x=$\frac{1}{4}$ | x-$\frac{7}{9}x=\frac{5}{12}$ | 5x+2x=5$\frac{3}{5}$ |
$\frac{2}{3}x+\frac{1}{2}x=\frac{7}{8}$ | x+$\frac{1}{5}$x=36 | $\frac{3}{5}$x+20=50. |
13.口算.
$\frac{4}{5}$×$\frac{5}{12}$= | $\frac{7}{15}$+$\frac{3}{15}$= | $\frac{5}{16}$×4= | 1÷$\frac{1}{6}$= |
$1-\frac{1}{8}-\frac{7}{8}$= | $\frac{4}{9}$×$\frac{5}{9}$×0= | $\frac{7}{4}$÷$\frac{3}{4}$= | ($\frac{1}{4}$+$\frac{3}{4}$)×56= |
12.小汽车有50辆,大卡车比小汽车多$\frac{1}{5}$.两种车一共有多少辆?正确列式是( )
A. | 50-50×$\frac{1}{5}$ | B. | 50+50×$\frac{1}{5}$ | C. | 50+50×(1+$\frac{1}{5}$) |
11.红红带了200元钱上街买东西,用去的钱数是余下的钱数的$\frac{3}{5}$,红红用去了( )元.
A. | 20 | B. | 75 | C. | 62.5 |
9.一项工程,甲单独做5小时完成,乙单独做3小时完成.甲、乙合做共需要多少小时?正确列式为( )
0 163173 163181 163187 163191 163197 163199 163203 163209 163211 163217 163223 163227 163229 163233 163239 163241 163247 163251 163253 163257 163259 163263 163265 163267 163268 163269 163271 163272 163273 163275 163277 163281 163283 163287 163289 163293 163299 163301 163307 163311 163313 163317 163323 163329 163331 163337 163341 163343 163349 163353 163359 163367 199269
A. | 1÷($\frac{1}{5}$+$\frac{1}{3}$) | B. | 1÷($\frac{1}{5}$÷$\frac{1}{3}$) | C. | 1÷($\frac{1}{5}$+$\frac{1}{3}$)×2 |