(80- 18)×(5+x)=80×5

62×(5+x)=400

3 10+62x=400

62x=90

x=45/3 1

A: It will take two more days to process.

2. Solution: Suppose there are x million science and technology books, then there are 2 million literature and art books.

x+2x=2.7

3x=2.7

x=0.9

2x=2×0.9= 1.8

A: There are 9,000 books on science and technology and 65,438+8,000 books on literature and art..

3. Solution: Assume that X pieces are produced every day on average.

6×64+2x=580

384+2x=580

2x= 196

x=98

A: On average, 98 units are produced every day.

4. Solution: X yuan buys basketball and 3 yuan buys football.

x+3x= 1 140

4x= 1 140

x=285

3x=3×285=855

A: It costs 285 yuan to buy basketball and 855 yuan to buy football.

5. Solution: Set the car B to travel at the speed of X kilometers per hour.

6×(49+x)=540

49+x =90

x =4 1

A: The speed of the second train is 4 1 km.

6. Solution: If Xiaohua is X years old this year and Grandpa is 8x years old this year.

8x-x=56

7x=56

x=8

8x=8×8=64

A: Xiaohua is 8 years old and Grandpa is 64 years old.