(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79简便运算999+24/25x(-5)

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/30 00:42:07
(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79简便运算999+24/25x(-5)

(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79简便运算999+24/25x(-5)
(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79简便运算
999+24/25x(-5)

(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79简便运算999+24/25x(-5)
(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79
=(-13)(-3.85-6.15)+0.79x(7/15+8/15)
=130+0.79
=130.79
999+24/25x(-5)
=999+(1-1/25)×(-5)
=999-5+1/25×5
=999-5+1/5
=994又1/5

(-3.85)x(-13)+(-13)x(-6.15)+0.79x7/15+8/15x0.79
=(-13)(-3.85-6.15)+0.79x(7/15+8/15)
=130+0.79
=130.79