(30+x) 10= 15x

300+ 10x= 15x

5x=300

x=60

15× 60 = 900m

A: It takes 60 minutes to climb this mountain, which is 900 meters high.

2.∫2 | x |- 1 = 0

∴2|x|= 1

∴x= 0.5

3. 1/4+5(x- 1/20 10)= 1/2

Solution:1/4+5x-1/402 =1/2.

5x=203/804

x=203/4020

3+ 10(2x- 1/ 1005)= 3+ 10(2x 203/4020- 1/ 1005)= 808/20 1

4. Solution: Assume that the remaining work will take X hours to complete.

4× 1/20+( 1/20+ 1/ 12)x = 1

1/5+2/ 15x= 1

2/ 15x=4/5

x=6

A: The rest of the work will take six hours to finish.

5. Solution: Set the scheduled time limit as X days.

20x+ 100 = 20( 1+0.2)x-50

20x+ 100=24x-50

4x= 150

x=37.5

37.5X20=750 (piece)

A: The worker originally planned to produce 750 parts, and the planned construction period was 37.5 days.

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