能简算的用简便方法计算.(写出主要简便过程,无过程不得分)
①1.6×3.9×1.25 | ②4.87×2.34+48.7×0.266 | ③0.05×0.7×20×1.7 |
④2.5×3.2×12.5 | ⑤3.95×7.6+3.95×3.4-3.95 | ⑥0.49×9.9. |
解方程(第②小题要写出检验过程)
①8×4-3x=2 | ②5x-2x=9.6 | ③25x÷2=100 |
①1.6×3.9×1.25 | ②4.87×2.34+48.7×0.266 | ③0.05×0.7×20×1.7 |
④2.5×3.2×12.5 | ⑤3.95×7.6+3.95×3.4-3.95 | ⑥0.49×9.9. |
①8×4-3x=2 | ②5x-2x=9.6 | ③25x÷2=100 |