Question

数学题,请快快解题,谢谢.

1.一段公路,第一天修了全长的五分之一,第二天修了全长的四分之一.
(1)两天一共修了90米,这段公路长多少米?
(2)第二天比第一天多修了20米,这段公路长多少米?
(3)结果还剩55米未修,这段公路长多少米?

2. 一辆汽车从福州开往厦门,已行了全程的五分之三,超过中心点35千米.福州与厦门相距多少千米?

Answer 1

1.(1)90/(1/5+1/4)=200m (2)20/(1/4-1/5)=400m (3)55/(1-1/5-1/4)=100m
2.35/(3/5-1/2)=350km

Answer 2

1.1/5x+1/4x=90 x=200
2.1/4x-1/5x=20 x=400
3.(1-1/5-1/4)x=55 x=100

4.3/5x-1/2x=35 x=350

Answer 3

200,400,100,350

Answer 4

(1)90/(1/5+1/4)=200
(2)20/(1/4--1/5)=400
(3)55/(1--1/5--1/4)=100
2 35/(3/5--1/2)=350

Answer 5

1 :1/5X+1/4x=90
x=200
2:1/4x-1/5X=20
x=400
3:1-(1/5X+1/4x)=55
x=100
4:3/5x=1/2x+35
x=350