Question

简便计算，求解，谢谢啦，急！！！

①7/9​×2/3​+7/9​÷3
②3.2÷4/5ⅹ25
③(1/2+1/4)ⅹ24
④1/13+12/13ⅹ(0.5-1/3)

Answer 1

①原式=(7/9)×(2/3) + (7/9)×(1/3)
=7/9 × (2/3 + 1/3)
=7/9 × 1=7/9
②原式=4×0.8÷0.8×25
=(4×25)×(0.8÷0.8)
=100×1=100
③原式=(1/2)×24 + (1/4)×24
=12 + 6=18
④原式=1/13 + (12/13)×0.5 - (12/13)×(1/3)
=1/13 + 6/13 - 4/13
=(1+6-4)/13=3/13

Answer 2

1、7/9×2/3+7/9÷3
=7/9×2/3+7/9×1/3
=7/9×（2/3+1/3）
=7/9×1
=7/9
2、3.2÷4/5×25
=3.2÷0.8×25
=4×25
=100
3、（1/2+1/4）×24
=1/2×24+1/4×24
=12+6
=18
4、1/13+12/13×（0.5-1/3）
=1/13+12/13×（3/6-2/6）
=1/13+12/13×1/6
=1/13+2/13
=3/13

Answer 3

答：①7/9×2/3+7/9×1/3

=7/9×（2/3+1/3）

=7/9×1

=7/9

---

②16/5×5/4×25

=4×25

=100

---

③1/2×24+1/4×24

=12+6

=18

---

④1/13+12/13×（1/2-1/3）

=1/13+12/13×1/2-12/13-1/3

=1/13+6/13-4/13

=3/13