quadratic equation,,比條式我就ok

1) The sum of a number and its reciprocal is 29/10. Find the possible values of the number.

2) Mabel pays $54 for N stickers. If the price of each sticker is increased by $1, she can only buy N-2 stickers by paying $10 more. Find the value of N.

3) A housewife pays $75 for some apples. If the price of each apple is reduced by $0.5, she can buy 5 more apples with the same amount of money. Find the original price of an apple.

4) Peter travels 20km in a journey. If his speed decreased by 1 km/h, the journey takes 1 hour more. Find the original speed of Peter.

5) If David walks at 1km per hour slower than his usual speed, then it takes him 30 mins more to walk a distance of 6 km. Find his usual walking speed.

6) A factory produces 40 cakes in N hours. If the factory produces 2 more cakes in each hour, then it will take 1 hour less to produce 40 cakes. Find the value of N.

7) A man bought N items of glassware for $720. 10 items were broken. By selling each of the unbroken items for $12 more than the original cost per item, he had no gain or loss. Find the value of N.

8) A man bought a certain number of rabbits for $1600. After one week,5 rabbits died. The man then sold the remaining rabbits each at $40 more than the original cost per rabbit. He made a total profit of $200. Find the number of rabbits that the man bought.

9)Martin can finish a job in N days and John can finish the same job in (N+2) days. If they work together, they can finish the job in 1/6(N+6) days. Find the value of N.