Question

三题数学题

(-7/2)+(+5/6)+(-0.5)+4/5+19/6=
(-26.54)+(-6.14)+18.54+6.14=
已知：a=-2,b=20,c=-3,且a-(-b)+c-d=10,求d的值。
要有过程

Answer 1

(-7/2)+(+5/6)+(-0.5)+4/5+19/6= （-7-1）/2+（5+19）/6+4/5=-4+4+4/5
=4/5

(-26.54)+(-6.14)+18.54+6.14=所有小数正负抵消，正负6抵消=-26+18
=-8

已知：a=-2,b=20,c=-3,且a-(-b)+c-d=10,求d的值。
D=a-(-b)+c-10
代入abc 可得
D=-2-(-20)+(-3)-10=20-5-10
=5

Answer 2

(-7/2)+(+5/6)+(-0.5)+4/5+19/6
=(-7/2-1/2)+(5/6+19/6)+4/5
=-4+4+4/5
=4/5

(-26.54)+(-6.14)+18.54+6.14
=(18.54-26.54)+(6.14-6.14)
=-8

已知：a=-2,b=20,c=-3,且a-(-b)+c-d=10,求d的值。
d=(a+b+c)-10=(-2+20-3)-10=5

Answer 3

(1) (-7/2)+(+5/6)+(-0.5)+4/5+19/6
=(-7/2)+(+5/6)+(-1/2)+4/5+19/6
=(-7/2)+(-1/2)+)+4/5+(+5/6)+19/6 前两项相加，后两项相加（加法的交换律）
=(-4)+4/5+4
=4/5
(2) (-26.54)+(-6.14)+18.54+6.14
=(-26.54)+18.54+(-6.14)+6.14
=-8+0
=-8
(3) 因为a-(-b)+c-d=10
所以 d=a-(-b)+c-10
=(-2)-(-20)+(-3)-10
=5

Answer 4

(-7/2)+(+5/6)+(-0.5)+4/5+19/6
=(-7/2)+(-0.5)+4/5+5/6+19/6
=-4+4/5+4
=4/5

(-26.54)+(-6.14)+18.54+6.14
=(-26.54)+18.54-6.14+6.14
=-8+0
=-8

a-(-b)+c-d=10
d=a+b+c-10
=2+20-3-10
=9

Answer 5

(-7/2)+(+5/6)+(-0.5)+4/5+19/6=
(-7/2)+(-0.5)+(+5/6)+19/6+4/5
=-4+4+4/5=4/5

(-26.54)+(-6.14)+18.54+6.14=
(-26.54)+18.54+(-6.14)+6.14=-8+0=-8

a=-2,b=20,c=-3 代入
a-(-b)+c-d=10得 -2-（-20）+（-3）-d=10
d=-2+20-3-10=5

Answer 6

(-7/2)+(+5/6)+(-0.5)+4/5+19/6=(-7/2-1/2)+(5/6+19/6)+4/5=-4+4+5/4=5/4
(-26.54)+(-6.14)+18.54+6.14=(-26.54+18.54)+(-6.14+6.14)=-8
d=a+b+c-10=5