Question

数学计算题有几题不会请求帮助

1、1.25+3/4-5/12-3/8
2、(1/2-3/4-5/8)除（-5/8)
3、7除（-7/12)×(1/2-1/3)

Answer 1

1. 1.25+3/4-5/12-3/8
= 5/4 + 3/4 - 5/12 - 3/8
= 8/4 - 5/12 - 3/8
= (48 - 10 - 9 ) / 24 = 29/24
2.(1/2-3/4-5/8) ÷（-5/8)
= ( 4/8 - 6/8 - 5/8) × (- 8/5)
= -7/8 × (- 8/5) = 7/5
3. 7÷（-7/12)×(1/2-1/3)
= 7× (-12/7) × 1/6
= -12 × 1/6
= -2

Answer 2

1.25+3/4-5/12-3/8=10/8+9/12-5/12-3/8=7/8+1/3=21/24+8/24=29/24
(1/2-3/4-5/8)除（-5/8)=-7/8×-8/5=7/5
7除（-7/12)×(1/2-1/3)=7×-12/7×1/6=-2

Answer 3

1.25+3/4-5/12-3/8
=5/4+3/4-5/12-3/8
=8/4-10/24-9/24
=2-19/24
=29/24
(1/2-3/4-5/8)/（-5/8)
=(4/8-6/8-5/8)/（-5/8)
=(-7/8)/（-5/8)
=7/5
[7/（-7/12)]×(1/2-1/3)
=[7/（-7/12)]×(6/12-4/12)
=[7/（-7/12)]×(2/12)
=(-12)×(2/12)
=-2

Answer 4

1、29/24
2、7/5
3、-2